JP3321167B2 - Valve control means - Google Patents

Description

The present invention relates to valve (ie, valve) control means for an internal combustion engine.

The valve control means of the present invention will be described in relation to the use of the valve control means in an internal combustion engine of a motor vehicle. However, it should not be construed that the present invention is limited to such use.

WO 91/12413 describes valve control means for controlling an intake valve and an exhaust valve of an internal combustion engine. Embodiments of the specification are illustrated, each showing a camshaft (camshaft) with a first cam and a second cam. Also, the second cam has a different profile (contour) than the first cam
Having. Means are provided for relaying the cam motion of the two cams to the intake or exhaust valves of the engine. The means for transmitting the reciprocating motion includes a first cam follower interlocking with an intake valve or an exhaust valve, a second cam follower operating relative to the first cam follower, and these two cam followers. Fixing means for connecting the parts to operate together. When the first cam follower and the second cam follower are not connected, the cam movement of the first cam is transmitted to the controlled valve by the first follower, and the valve lift is controlled by the first cam profile. Obey. When the first cam follower and the second cam follower are connected, the cam movement of the second cam is relayed to the controlled valve by the first cam follower and the second cam follower. The lift of the controlled valve is controlled by the second cam profile.

The fixing means of the system described in WO 91/12413 are operable under hydraulic control. The fixing means is controlled by controlling the lift of the controlled valve at a low engine speed by the cam profile of one of the two cams, and at a high engine speed by the cam profile of the other cam. That's why. This is an advantage over existing engines. This is because the relationship between the valve lift and the crankshaft position can be varied according to the speed of the engine, and the engine efficiency can be maximized.

The valve control means described in WO91 / 12413 is provided with a hydraulic lifter (hydraulic lash adjuster, that is, a hydraulic valve lifter). Hydraulic lifters are well known in the art and are used to compensate for wear of components in the valve power transmission path. With the hydraulic lifter, the components of the valve control means are
Even if worn, it is possible to more reliably maintain the contact state of each part.

Modern engines also have severe restrictions on the packaging of the valve control means. This is even more so with engines that use four valves per cylinder. For this reason, the valve control means used should be as compact as possible.

The first cam follower of the valve control means of WO 91/12413 is a bucket tappet, which can slide in a bore provided in the second cam follower. Bucket tappets are well known in prior art engines. WO91 / 12413
In this system, the hydraulic lifter operates between the bucket tappet and the controlled valve, and the stem of the controlled valve is now in direct contact with the hydraulic lifter. WO91
The details of the valve control means of / 12413 will be described later with reference to one of the figures of the present application.

The bucket tappet used in the conventional engine,
It is common for the diameter to be in the range of 19 to 40 millimeters. The size of the tappet must be such that it draws out the mechanical advantage (i.e., mechanical magnification) required by the cam profiles used in conventional engines. The mechanical magnification is obtained by moving the contact point between the tappet and the cam lift portion away from the center axis of the tappet. Here, there is a minimum allowable distance in order to obtain the valve acceleration required for the cam profile suitable for full speed operation of the engine or high speed operation, and the minimum area of the tappet to be used 7 is determined according to this distance. . Such a geometric relationship exists between the cam profile lift speed and the area of the tappet used.

Some push rod engines use hydraulic lifters. In this hydraulic lifter, one component forming an extendable chamber for hydraulic oil directly contacts the cam, and the other component is connected to a push rod.
However, such valve lifters (rush adjusters) have not been used in overhead camshaft type engines, as far as we know. Furthermore, valve lifters currently used in push rod engines are typically 19 mm or more in outer diameter. This is because the cam profile used in a push rod engine requires that this valve lifter have some minimum area.

A valve control means according to the present invention is a valve control used in an internal combustion engine including a valve means, and a cam means including a rotatable camshaft having a first portion and a second portion having a different cross-sectional shape from the first portion. Means, provided to be interlocked with the valve means, a first follower means provided so as to be interlockable with the first portion, and provided movably relative to the first follower means, A second follower means provided so as to be interlockable with the two parts; and a connecting means provided so as to connect the first follower means and the second follower means, wherein the first follower means is provided. A first member having a lumen having a closed bottom surface, and a first member which is provided so as to be movable in the lumen of the first member and forms a variable volume chamber for hydraulic fluid together with the first member. Two members, provided so that fluid flows into the variable volume chamber; Conduit means, and valve means for controlling the flow of fluid to the variable volume chamber, comprising hydraulic lift means, wherein the first follower means and the second follower are used when the valve control means is in use. When the means is not connected, the movement of the valve means is controlled by the first follower means, and the valve means moves by receiving the lift of the first part every cycle of the engine, and the first driven When the joint means and the second follower means are connected, the movement of the valve means is controlled by the second follower means, and the valve means controls the lift of the second part every cycle of the engine. In the valve control means, which receives and moves, a sliding surface in contact with the first portion is provided on an outer surface of the first member of the hydraulic lift means.

The applicant understands that one of the follower portions of the present invention is configured to be driven by a low-lift cam (or a non-lift lobe described later) designed for low-speed operation, so that this cam and It is possible to reduce the area of the interlocked follower (the minimum required area is directly proportional to the lift). Therefore, the bucket tappet of WO91 / 12413 is no longer necessary, and the size of the valve control means can be reduced.

The valve control means of WO 91/12413 can be used for engines equipped with existing bucket tappets and hydraulic lifters. In this case, the valve control means is simply arranged in the bucket tappet provided in the engine and the bore for the hydraulic lifter. However, the valve control means of WO 91/12413 can only be installed in a limited range of engines due to the overall size of the valve control means. Since the valve control means of the present invention can be made more compact than the valve control means of WO91 / 12413, the valve control means can be provided in a wider range of engines.

In the present invention, preferably, the second follower means is provided with a lumen, the first follower means is slidably disposed in the lumen, the cross-sectional shape of the lumen, the The cross-sectional shape, shape and size of the portion of the first member that slides with the inner cavity of the hydraulic lift means are set to be compatible.

Also preferably, said first follower means and said second follower means are cylindrical, and said first follower means has a diameter in the range of 8 mm to 18 mm.
Prior art bucket tappets range from 19mm to 40mm
It typically has a diameter of millimeters.

Thus, the first follower has a first diameter and the second follower has a larger second diameter. Both diameters are
At least each must have a minimum value to allow for lift of the first and second cams (if two cams are used). However, the first diameter can be made smaller than the second diameter by operating the first follower means with a lower lift cam (or a no-lift curve described later) than the second follower means during operation.

Still preferably, the present invention includes an engaging means provided on an outer surface of the first member of the hydraulic lift means, and the connecting means uses the engaging means to form the first driven joint means and the second driven Connect with the knot means.

Thus, the coupling means engages the outer surface of the hydraulic lift means. It does not engage with bucket tappets (as in the prior art).

In the internal combustion engine according to the present invention, in the internal combustion engine having the above-described valve control means, a sliding surface of the first member of the hydraulic lift means directly contacts a part of the camshaft.

In an engine using valve control means of WO 91/12413, the hydraulic lift means contacts a bucket tappet, which contacts a portion of the camshaft. On this occasion,
As a conventional general technique, a hydraulic lifter is provided inside a bucket tappet. In the present invention, the configuration of the above-mentioned prior art is unnecessary.

In the present invention, when the internal combustion engine is an overhead camshaft type engine provided with a poppet valve that operates to open and close a port (intake / exhaust port) of a cylinder, preferably, the poppet valve is provided with the hydraulic pressure. Direct contact with the second member of the lifting means.

According to the above-described invention, there is an advantage that the valve train can be made lighter by not including the bucket tappet in the valve train.

On the other hand, when the internal combustion engine is a push rod type engine, the push rod is preferably connected to the second member of the hydraulic lift means.

In the second aspect, the valve control means according to the present invention comprises:
Valve control means for use in an internal combustion engine comprising: valve means; and a cam means including a rotatable camshaft having a first portion and a second portion having a different cross-sectional shape than said first portion, wherein said valve means comprises: The first follower means is provided so as to be capable of interlocking with the first portion, and is provided so as to be relatively movable with respect to the first follower means, and is provided so as to be interlockable with the second portion. A second follower means, and a connecting means provided so as to connect the first follower means and the second follower means, wherein the first follower means has a closed bottom surface. A first member provided with a cavity, a second member provided movably in the inner cavity of the first member, and forming a variable volume chamber for hydraulic fluid together with the first member; and Conduit means provided for the flow of fluid, said volume variable And a valve means for controlling the flow of fluid to the valve, the hydraulic control means comprising: if the first follower means and the second follower means are not connected in use of the valve control means, The movement of the valve means is controlled by the first follower means, and the valve means moves by receiving the lift of the first portion, and the first follower means and the second follower means are connected. If so, the movement of the valve means is controlled by the second follower means, the valve means moves in response to the lift of the second part, the second follower means is provided with a lumen, The valve follower, wherein the first follower means is disposed in the lumen so that at least a portion of the first member of the hydraulic lift means slides with the lumen. The cross-sectional shape of the lumen is the same as that of the first member of the hydraulic lift means. It is characterized in that the cross-sectional shape and shape and size of the portion to slide is set to match.

Here, preferably, the lumen has a circular cross section, the cross section of the first member of the hydraulic lift means has a circular outer peripheral shape, and the diameter of the lumen is the third of the hydraulic lift means. It is a size that fits the outer diameter of one member.

In a third aspect, a valve control means according to the present invention comprises: an internal combustion engine comprising: a valve means; and a cam means including a rotatable camshaft having a first portion and a second portion having a cross section different from the first portion. A valve control means used in an engine, wherein the first follower means is provided so as to be able to interlock with the valve means, and is provided so as to be able to cooperate with the first portion, and moves relatively to the first follower means. A second follower means provided so as to be capable of interlocking with the second portion, and a connecting means provided so as to connect the first follower means and the second follower means. The first follower means is provided with a first member having a lumen having a closed bottom surface, and is provided movably in the lumen of the first member, and for the hydraulic fluid together with the first member. A second member forming a variable volume chamber;
Conduit means provided so that fluid flows into the variable volume chamber, and valve means for controlling the flow of fluid to the variable volume chamber, including hydraulic lift means, and in use of the valve control means, When the first follower means and the second follower means are not connected, the movement of the valve means is controlled by the first follower means, and the valve means controls the first part for each cycle of the engine. When the first follower means and the second follower means are connected, the movement of the valve means is controlled by the second follower means, and the valve means The valve control means, which moves upon receiving a lift of the second portion for each cycle of an engine, includes an engagement means provided on an outer surface of the first member or the second member of the hydraulic lift means, The connecting means is the engaging means It is characterized in that for connecting the said second follower means and the first follower means used.

Preferably, the engaging means is provided on an outer surface of the first member of the hydraulic lift means.

Also preferably, the engagement means includes a recess provided on an outer surface of a first member of the hydraulic lift means, and the connection means is provided on the second driven joint, and A locking pin extends and engages the recess.

As described above, in the present invention, the hydraulic lift means is in direct contact with the camshaft portion (without the interposition of the bucket tappet), and the overall diameter of the valve control means is smaller than that of the prior art valve control means. WO91 / 1
It is more advantageous than the valve control means as described in 2413.

In the present invention, preferably, the first portion of the camshaft is a first cam having a first cam profile, and the second portion of the camshaft has a second cam profile different from the first cam profile. A second cam, wherein the first follower means includes a first cam follower means provided so as to be interlockable with the first cam, and the second follower means is capable of interlocking with the second cam. And the second cam follower means provided on the second cam.

On the other hand, unlike the above, the first portion of the camshaft may have a circular cross-sectional portion set such that the valve means does not lift, in which case the second portion of the camshaft is a cam, The second follower unit includes a second cam follower unit provided so as to be interlocked with the cam.

In a fourth aspect, the present invention is an overhead camshaft type engine comprising a rotatable camshaft, valve means, and a hydraulic lifter operating between the valve means and a portion of the camshaft, The hydraulic lifter is provided so as to be movable in a first member having a lumen having a closed bottom surface and a lumen having the closed bottom surface, and forms a variable volume chamber together with the first member. An overhead camshaft type engine, comprising: a second member, conduit means provided so that fluid flows into the variable volume chamber, and valve means for controlling inflow and outflow of the fluid into the variable volume chamber. The part of the camshaft slides directly on a sliding surface provided on the first member of the hydraulic lifter.

In creating a new valve control design as described above, Applicants have invented and designed a new type of hydraulic lifter for overhead camshaft type engines.

In the overhead camshaft type engine of the present invention, preferably, the first member has a cavity, and the conduit means includes a first passage communicating the cavity with the outside of the first member; A second passage communicating between the cavity and the variable volume chamber, wherein the valve means controls a flow of a fluid from the cavity to the variable volume chamber.

In order to operate the hydraulic lifter effectively, the variable volume chamber is preferably positioned as low as possible so that oil can easily flow into the chamber by the action of gravity. The design reflects this point and also places the larger cross-sectional component of the valve lifter at the highest position to slide with the cam.

In the present invention, preferably, the third passage is provided so as to connect the hollow portion to the sliding surface provided in the first member and to allow the sliding surface to be lubricated with oil from the cavity. Including.

The third passage provides lubrication and prevents airlock in the hydraulic lifter.

The preferred embodiments of the present invention will now be described with reference to the accompanying drawings.

 FIG. 1 shows a prior art valve control means.

FIG. 2 is a cross-sectional view of the first embodiment of the valve control means according to the present invention, and shows a cross-sectional view taken along a line BB of FIG.

FIG. 3 is a cross-sectional view of the valve control means of the first embodiment shown in FIG. 2, and shows a cross-sectional view taken along a line AA in FIG.

FIG. 4 is a cross-sectional view of the valve control means of the first embodiment, showing a cross-sectional view when the valve control means is used in an internal combustion engine under a first operating condition.

FIG. 5 is a sectional view of the valve control means according to the first embodiment of the present invention, showing a sectional view when the valve control means is used in the internal combustion engine under the second operating condition.

FIG. 6 is a cross-sectional view of a second embodiment of the valve control means according to the present invention, and shows a cross-sectional view of the line DD in FIG.

FIG. 7 is a cross-sectional view of the second embodiment shown in FIG. 6, showing a cross-sectional view taken along a line CC in FIG.

FIG. 8 is a cross-sectional view of a third embodiment of the valve control means according to the present invention, and shows a cross-sectional view taken along a line FF in FIG.

FIG. 9 is a cross-sectional view of the third embodiment shown in FIG. 8, and shows a cross-sectional view of the line EE in FIG.

First, the prior art valve control means will be described. WO91
1, camshaft 10 is shown. The camshaft 10 includes a first cam 11 of a first cam profile, and two cam portions 12 and 13.
The cam sections 12 and 13 each have the same cam profile, but differ from the cam profile of the cam section 11.

FIG. 1 shows the prior art valve control means in a first operating condition. In the first operating condition, the intake valve 14 is controlled by the profile of the cam 11.

As shown in FIG. 1, the valve control means 15 of the prior art system includes an outer cam follower section 16 having a cylindrical shape, an inner cam follower section 17 slidable in the lumen of the outer cam follower section 16, and Is provided.

In the prior art embodiment, the inner cam follower 17 comprises a bucket tappet 18, which is well known in the prior art. The hydraulic lifter comprises members 19 and 20 and is located in the bucket tappet 18.

The member 20 is in contact with the top of the intake valve 14, and the outer diameter of the member 20 matches the inner diameter of the bucket tappet 18. The member 19 is in contact with the bucket tappet 18 and can slide inside the member 20. In a known manner, members 19 and 20 form a chamber between each other and are provided with a check valve to control the flow of oil into this chamber. Oil flows freely into this chamber, but outflow from the chamber is prevented by a check valve. The members 20 and 19 move relative to each other and extend the chamber formed therebetween to compensate for wear of components of the valve control mechanism, for example, wear of the cams 11, 12, and 13.

Thus, the internal cam follower is a bucket tappet
It should be appreciated that the system includes a hydraulic lifter 18 and the hydraulic lifter operates between the bucket tappet 18 and the valve 14.

Referring now to FIG. 2, a valve control means according to the present invention is shown. The valve control means includes a first cam follower 100 that can move through a lumen provided in a second cam follower 150.

The first cam follower section 100 performs a hydraulic lift (by-drill-like lash adjustment, that is, hydraulic clearance adjustment). The first cam follower 100 includes an upper member 101, which has a friction surface that slides on the cam. The upper member 101 in FIG. 2 is composed of two parts 101A and 101B.
The two parts are in close contact with each other. Generally, portion 101A is made of alloy cast iron and portion 101B is made of steel.

The upper member 101 usually has a cylindrical shape. An upper cavity 102 is provided in the member 101 and communicates with the outside of the member 101 through a passage 103. The cavity 102 is
Is also communicated with the sliding surface of the member 101 via. The cavity 102 is cylindrical, and has a passage 106 facing downward from the lower end thereof.

The member 101 also has a lower cavity and has a larger diameter than the upper cavity 102. The lower member 107 of the first cam follower 100 can slide relative to the member 101 in the lower cavity.

The lower member 107 and the upper member 101 form a chamber 108 therebetween. The chamber 108 can communicate with the chamber 102 via the passage 106. Check valve means are provided to control the flow of oil through the passage 106. The check valve means includes a valve retainer 109, a ball 110, a ball 110 and the valve retainer 109.
Between the light spring 111 and the upper member 1
Spring 1 operating between 01 and lower member 107
12 is provided.

The outer diameter of the lower member 107 of the first cam follower means 100 matches the diameter of the lower cavity of the upper member 101.

The second follower means 150 includes a first member 151, and the first member 15
1 has a surface that slides on the cam. Typically, member 151 is of the cylindrical type, typically made of cast iron alloy. A skirt 152 is attached to member 151, which is typically made of steel, and is also typically cylindrical. The outer diameter of the outer steel skirt 152 matches the maximum diameter of the member 151.

The skirt 152 has a reduced diameter portion that forms an annular recess 154. This reduced diameter portion also forms an annular seat 155 into which a spring fits.

An annular cavity 156 is formed between the member 151 and the skirt 152. The annular cavity 156 communicates with the annular recess 154 via a passage 157.

The fixing pins 160, 161, 162 are shown in FIG. The fixing pin 160 is also shown in FIG. All three fixing pins are identical to one another and are similarly mounted in member 151. Therefore, only the fixing pin 160 will be discussed in detail.

The fixing pin 160 is slidable in a radially extending lumen in the member 151. A spring 163 is provided and operates between the enlarged diameter portion of the fixing pin 160 and the member 151 to urge the fixing pin 160 radially outward. The fixing pin 160 pressed by the spring 163 contacts the skirt 152 made of steel. The rear of the fixing pin 160 is flat, but the inner surface of the skirt 152 is cylindrical, so that the fixing pin 1
A cavity 167 is created between 60 and skirt 152 even when they are in contact with each other. A passage 164 is provided in member 151 to allow communication between cavity 167 and cavity 156.

The fixing pin 160 is configured to slide radially in a lumen in the member 151 and engage with a concave portion 165 formed on the outer surface of the member 101 of the first cam follower.

A lumen 166 is provided in the fixing pin 160, and a recess 165 is provided.
And a cavity formed between the fixing pin 160 and the member 151. A groove 168 is provided on the surface of the member 101 to enable communication between the concave portion 165 and the bottom surface of the member 101 via the passage 170.

A pin 149 is provided to extend inward from the cam follower means 150. The pin 149 is the cam follower
Is engaged with the groove 148 extending vertically. Pin 1
49 prevents the relative rotation occurring between the cam follower means 100 and 150.

FIGS. 4 and 5 show how the valve control means is used in the internal combustion engine of the first preferred embodiment.

FIG. 4 shows a low speed operation of the internal combustion engine. The figure shows an intake valve 180 of a cylinder of an internal combustion engine. Also, as shown in the figure, three cams 181, 182, 183 are provided on the camshaft 185, and rotate with the camshaft 185. Cam 181 has a first low lift cam profile, and cams 182, 183 each have the same high lift cam profile.

The intake valve 180 is a poppet valve and is provided together with the spring retainer 186. Spring retainer 186
And a valve spring 187 is actuated between the engine and the cylinder head of the engine, shown schematically at 188. Spring 187
Operates to draw the poppet valve 180 to its valve seat 189.

The valve control means of the present invention is provided in a bore in the cylinder head 188, and is slidable in the bore. The cylinder head 188 is provided with an oil gallery (i.e., a passageway for oil) 190 which communicates with the annular recess 154 of the member 152 when the valve control means is located in the lumen.

A spring 192 is provided to operate between the spring seat 155 of the valve control means and the cylinder head 188 to press the second cam follower 150 into contact with the two cams 182 and 183.

Under the operating conditions shown in FIG. 4, the oil pressure in oil gallery 190 is kept at a low level. Oil pressure is transmitted from the oil gallery 190 to the annular cavity 156 of the valve control means via the recess 154 of the valve control means. Thereafter, the hydraulic pressure is relayed in the passage 164 and transmitted to the cavity 167. This cavity 167 is formed behind the fixing pin (fixing pin 160 is shown in the figure).
Since the low level of hydraulic pressure is not strong enough to overcome the biasing effect of the spring 163, the fixed pin 160 (and other fixed pins 161, 162) remains retracted in the cam follower 150 and The joint 150 has no connection with the cam follower 100.

Since the cam followers 100 and 150 are not connected, they move independently of each other. The cam follower 100 slides on the surface of the cam 181 to transmit the cam movement of the cam 181 to the intake valve 180. This is,
The lift A shown in FIG.

Equipped with control means in the internal combustion engine, the oil gallery 19
Control the oil pressure within 0. When the engine reaches a certain speed, the control means typically switches the hydraulic pressure and converts from low pressure to high pressure. Fig. 5 shows the oil gallery
The pressure in 190 is switched to high pressure, high pressure oil is transmitted, and acts on fixing pins 160, 161, 162. The three fixed pins engage the internal cam follower 100 and connect the cam followers 100 and 150 so that they move together. Thus, the intake valve 180 is controlled by the profiles of the cams 182 and 183. This profile is a higher lift profile than the cam 181 profile. Figure 5 shows the increase in valve lift
B of FIG. Since cams 182 and 183 have a higher lift than cam 181, inner cam follower 100
Although it does not slide with 81, the cam follower 150 slides with the high lift portions of the cams 182 and 183. This is shown in FIG.

When the engine speed returns below a certain level, the pressure in oil gallery 190 returns to a low level and spring 163
Moves the fixing pins 160, 161, 162 to disengage the internal cam follower 100. As a result, the cam follower 100
And 150 are disconnected and valve 180 is again controlled by the profile of cam 181.

The engagement between the fixed pin and the internal cam follower 100 is performed only when the cam followers 100 and 150
Only when they are aligned in a straight line while sliding with the 183 base circles. This is advantageous for ensuring smooth switching. Furthermore, fixing pins 160, 16
Due to the friction between the cam follower 100 and the cam follower 100, the fixing pin can be retracted when the cam follower is sliding with the base circle of the cam 181, 182, 183. Limited. This is also advantageous for ensuring smooth switching.

When the fixing pins 160, 161 and 162 move radially inward due to hydraulic pressure, the oil may stagnate between the fixing pin and the cam follower 150, thereby causing a hydraulic lock. It is important that you do not. In the first preferred embodiment of the invention described above, this is prevented by providing a passage 166. The passage 166 allows oil to flow out of the chamber formed between the fixed pin 160 and the cam follower 150 when the fixed pin 160 is moving radially inward. The oil that has flowed out of this chamber flows into the recess 165 formed on the outer surface of the internal cam follower 101 via the passage 166. Then, it flows out of the concave portion 165 and goes down the groove 168.

The hydraulic lift means of the present invention receives refueling when the cam followers 100, 150 slide with the base circles of the cams 182, 181, 183 in either of the two operating conditions. The components in the valve control means wear, and the cam and valve 180 wear, but at the same time, the spring 112 is actuated, pushing the member 107 away from the member 101 and moving from the top chamber 102 through the passage 106. To draw oil into the bottom chamber 108. The spring 112 is much more resilient and has a higher spring constant than the light spring 111, and the light spring 111 has a ball 110
Only serves to place the in a position adjacent to the passage 106. The member 107 moves only in a direction away from the member 101. This means that when compressive force is applied to both members 101 and 107,
This is because the ball 110 operates to stop the flow of the oil flowing from the chamber 108 to the chamber 102.

The chamber 102 receives the supply of hydraulic oil via the passages 103 and 179. This oil is refueled from cavity 156. The cavity 156 passes through the passage 157 and the annular cavity 154, and the oil gallery 19
The order is from 0 to refueling.

Passageway 104 serves to allow oil to flow from chamber 102 to the top surfaces of cam followers 100 and 150. Therefore, hydraulic oil lubricates the surface of the cam follower, reduces wear,
2 Prevent air from entering.

The hydraulic lift means of the present invention has features not found in prior art hydraulic lift means that a bucket tappet is not required. Therefore, the valve control means of the present invention can be more compact than the conventional one. Instead, one of the members forming the variable volume chamber of the hydraulic lifter has a friction surface, which slides directly on the cam (or WO
Sliding with a rocker arm located between the cam and the follower, as shown in one of the embodiments of 91/12413). This member has a recess formed on the outer surface, and the recess can be engaged with the fixing pin. Thus, the diameter of the lumen of the outer cam follower 151 can be reduced compared to the lumen of the prior art valve control means. This is because there is no need to provide a bucket tappet in the lumen.
Alternatively, the cross-sectional area of the lumen can be smaller. Its size is the same as the cross-sectional area of the larger largest part of the two members forming the extendable chamber of the hydraulic lifter.

Next, a second preferred embodiment of the present invention shown in FIGS. 6 and 7 will be described. The second preferred embodiment is similar in most respects to the first preferred embodiment, and similar components are numbered similarly.
For example, the member number 200 is used instead of the member number 100.

For the second preferred embodiment, only the differences from the first preferred embodiment will be discussed.

In a second preferred embodiment, the second cam passive node 250 is slightly different in shape, but remains generally cylindrical. An internal steel skirt 230 is provided in the second embodiment. The skirt 230 is attached to the body 251 of the cam follower 250.
And the lower end also has an external steel skirt 25
It is attached to 5.

The fixing pins 260, 261 and 262 have an L-shaped cross section. A spring 263 is provided to operate between the lower portion of the fixing pin and the inner steel skirt 230. The internal steel skirt is provided with an opening, as shown at 278, to open a cavity formed around the spring 263 and to pass through the groove 229 to prevent hydraulic fixing. The groove 229 is provided in the axial direction along the outer surface of the cam follower 200. The fixing pin 260 has a groove 228 on the top surface as shown. The groove 228 is a recess provided on the outer surface of the cam follower 200.
The oil flows from 265 so as to enter the groove 229. Groove 229
Allow this oil to flow to the top surface of the cam follower.

8 and 9 show a third preferred embodiment of the present invention. This preferred third embodiment is very similar to the previously described preferred second embodiment, so only the differences will be discussed.

The most important difference between the second and third embodiments is that the third embodiment uses only two fixing pins, 360 and 361. The fixing pins 360 and 361 have an L-shaped cross section as described above.

In the third embodiment, a spring 363 that performs a one-sided action is provided.
There is a different configuration of the oil passage device in the cavity surrounding the.
Each of the fixing pins 360 and 361 has a tapered tip, and a passage runs through the fixing pin. The passage includes a cavity surrounding the spring 363 and a cam follower joint 3.
00 and the concave portion 365 formed on the outer surface thereof. The tapered parts of the fixing pins 360 and 361 are filled with oil
It is also possible to flow through a groove formed on the outer surface of the cam follower section. Such grooves relay oil to the top surfaces of the cam followers 300, 350.

In each of the embodiments described above, the valve control means is designed to rotate freely within the bore in the cylinder head, thereby allowing the cam to follow different portions of the cam follower surface. It should be recognized that it is activated to reduce wear.

All three preferred embodiments of the present invention have common inventive features to be evaluated. This feature is that the internal cam follower has a hydraulic lifter,
That is, it slides with the cam without the need for a bucket tappet. In this way, the internal cam passive node can be reduced in diameter compared to the prior art, thus reducing the overall diameter of the valve control means. This is very important, as it fits the constraints of packaging in the engine.

Instead of having two cams of different profiles, the low lift cam can be replaced by a lobe of circular cross section. This lobe holds the valve off when the engine is slow (the circular lobe has no lift at all).

The applicant also proposes the following form. That is, the arrangement of the fixing pins allows the external cam follower to move slightly downward while the internal cam follower and the external cam follower are connected. At this time, a setting is made so that the outer cam follower can move somewhat from the sliding position of the two sliding cams to the base circle to a position where the inner cam follower starts to move downward. This can be achieved by appropriately setting the size of the concave portion outside the internal member. This feature ensures that maladjustments caused by wear are addressed and that the force of the valve spring is transmitted to the base circle of the low lift cam (or no lift lobe), whether the engine is low or high speed. Thus, under all conditions, the hydraulic lifter makes adjustments corresponding to the wear of the most worn components (low lift cam or no lift loaf). This arrangement ensures that the valve returns to its seat at low and high engine speeds, despite differences in wear between the camshaft cams (or no lift lobe and camshaft cams). Is attached.

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F01L 13/00 301 F01L 1/14 F01L 1/24

Claims (6)

(57) [Claims] 1. A rotatable cam having a poppet valve (180) and cam means, the cam means having a first portion (181) and a second portion (182) having a different cross-sectional shape than the first portion (181). A valve control means used for an overhead camshaft type internal combustion engine including a shaft (185), wherein the first driven means (100) is operable in conjunction with the poppet valve (180) and operable with the first portion (181). ) Is provided, and the first driven means is a hydraulic lash adjuster means (101A, 101B, 102, 103, 104, 106, 107, 108, 109, 1).
10, 111, 112), wherein the hydraulic lash adjuster means is provided movably in the first member (101A, 101B) having a hole and in the hole of the first member (101A, 101B). A second member (107) forming a variable volume chamber (108) for hydraulic fluid together with the first member (101A, 101B), and a conducting means (102, 102) for flowing fluid into the variable volume chamber (108).
103, 106) and check valve means (10, provided on the first member, for controlling the flow of fluid to the variable volume chamber (108).
9, 110, 111), and the second driven means (150) is provided so as to be relatively movable with respect to the first driven means (100) and operable with the second portion (182), In the hole provided in the second driven means (150), the first member (101A, 101A) constituting the hydraulic lash adjuster means of the first driven means (100) is inserted.
B) at least a part of the first driven means (100) is slidably arranged,
And the second driven means (150) are provided so as to be connectable, and the first driven means (10
0) and the second driven means (150) are not connected, the movement of the poppet valve (180) is controlled by the first driven means (100), and the poppet valve (180) The lift of the first part (181) is provided every engine cycle, and the movement of the poppet valve (180) is performed when the first driven means (100) and the second driven means (150) are connected. Is controlled by the second driven means (150), and the poppet valve (180) is provided with a lift of the second portion (182) for each engine cycle. The cross-section of the formed hole is set so that the cross-section and the shape and size of the cross-section of the sliding portion of the first member (101A, 101B) of the hydraulic lash adjuster means that slides in the hole. The hydraulic lash adjuster means Two members (10
7) contacts the poppet valve (180) and the first member (101) of the hydraulic lash adjuster means.
A, 101B) on the outer surface of the first driven means (100) and the second driven means (15) by the connecting means (160, 163, 167).
0) The valve control means, wherein an engagement means (165) for enabling the connection of (0) is provided. 2. The valve control means according to claim 1, wherein said first driven means (100) and said second driven means (150).
Is a cylindrical shape, and said first driven means (100) has a diameter in the range of not less than 8 mm and not more than 18 mm. 3. The valve control means according to claim 1, wherein said engagement means is a recess provided on an outer surface of said first member of said hydraulic lash adjuster means.
The connecting means (160, 163, 167) includes a fixing pin (160) provided on the second driven means (150),
Valve control means characterized in that said fixing pin extends from said second driven means (150) and engages with said recess (165). 4. The valve control means according to claim 1, wherein the first portion (181) of the camshaft (185) is a first cam having a first cam profile. The second portion (182) of the shaft (185) is a second cam having a second cam profile different from the first cam profile, and the first driven means (100) can interlock with the first cam. And a second cam follower provided to be able to interlock with the second cam. 5. The valve control means according to claim 1, wherein the first portion (181) of the camshaft (185) is set so that the poppet valve (180) does not lift. A second section (182) of the camshaft (185) is a cam, and a second cam follower capable of interlocking with the cam is provided on the second follower (150); Valve control means characterized by the above-mentioned. 6. The valve control means according to claim 1, wherein said first member (101) of said hydraulic lash adjuster means is provided.
A, 101B) is provided with a sliding surface which is in direct contact with the first portion (181) of the camshaft (185) on the outer surface thereof.