WO2019000646A1 - Valve assembly, piston unit and oil damper - Google Patents

Abstract

Disclosed is a valve assembly (22) arranged on a piston body (21) of an oil damper (3), wherein a valve cover (221) is provided with a fluid hole (2213). Oil above the piston body (21) successively passes through the fluid hole (2213) and a discharge hole (211) so as to realize unloading and vibration-damping functions, thus avoiding the geometrical tolerance between a valve cover (121) and a valve core (122) being influenced when an unloading opening (1222) is machined in a side wall of a blind hole (1221) of the valve core (122) in the prior art, thereby ensuring that the valve cover (221) and a valve core (222) fit precisely and further making the valve assembly (22) have a stable quality and a stable precision performance. Further disclosed is a piston unit (2) applied to the oil damper (3) and provided with the valve assembly (22) mentioned above, wherein same has a stable quality and stable precision performance. Further disclosed is an oil damper (3) provided with the piston unit (2) mentioned above, wherein same has a stable quality and stable precision performance.

Description

Valve body assembly, piston unit and oil damper Technical field

The present application relates to the technical field of hydraulic dampers for railway rolling stock, and more particularly to a valve body assembly, a piston unit and a hydraulic damper.

Background technique

The hydraulic damper for a railroad locomotive includes a working cylinder and a piston unit disposed in the working cylinder, the working cylinder being filled with oil, that is, the piston unit is filled with oil above and below. Referring to Figures 1 and 2, the piston unit 1 includes a piston body 11, the top of which is provided with one or more valve body assemblies 12, each of which includes a valve cover 121, a valve Core 122 and spring 123. The valve cover 121 and the valve core 122 are both cylindrical. The outer surface of the valve cover 121 is screwed to the piston body 11. The valve cover 121 is axially disposed with a through hole 1211. The valve core 122 is disposed. The through hole 1211 is disposed in the through hole 1211, and the through hole 1211 guides the movement of the valve core 122, and the outer surface of the valve core 122 is clearance-fitted with the inner surface of the through hole 1211, thereby closing the oil passage. The valve core 122 is axially disposed with a blind hole 1221. The bottom side wall of the blind hole 1221 is provided with a square unloading port 1222, and one end of the valve core 122 is connected to the piston body 11 through a spring 123 so that The valve body 122 is movable up and down, and the valve core 122 is provided with an oil sealing portion 1223. The spring 123 can press the upper surface of the oil sealing portion 1223 to fit the lower surface of the valve cover 121. In the closed oil passage, a discharge port 111 is disposed at a position on the bottom surface of the piston body 11 corresponding to the valve body 122; when the piston body 11 moves upward, the flow direction of the oil is as shown in FIG. 2 The upward movement of the piston body 11 causes the oil pressure above the piston body 11 to increase as indicated by the dashed line. The spool 122 is moved downward under the pressure of the oil, the unloading port 1222 is separated from the inner surface of the through hole 1211 of the valve cover 121, and the oil above the piston body 11 sequentially passes through the spool 122. The blind hole 1221, the unloading port 1222, and the discharge port 111 of the piston body 11 flow from below the piston body 11 into the lower portion of the piston body 11, thereby completing the unloading process and achieving the vibration damping effect. In order to make the hydraulic damper have a bidirectional unloading and damping effect, the bottom of the piston body 11 is further provided with the valve body assembly 12, the valve body assembly 12 at the bottom of the piston body 11 and the top of the piston body 11 The valve body assemblies 12 are offset from one another and staggered.

It can be seen from the above that the clearance between the inner surface of the valve cover 121 and the outer surface of the valve body 122 is ensured to stably and smoothly guide the up and down movement of the valve core 122. Therefore, the inner surface of the valve cover 121 is The fit tolerance between the outer surfaces of the spool 122 has a very important influence on the valve body assembly 12 and the piston unit 1, as well as the mass stability of the entire hydraulic damper. However, in the process of processing the unloading port 1222, the outer surface of the valve body 122 is inevitably clamped, and the outer surface of the valve core 122 is also impacted by a sudden force from the machining tool, thereby affecting the outer surface of the valve body 122. The cylindricity and the perpendicularity affect the clearance tolerance between the inner surface of the valve cover 121 and the outer surface of the valve body 122, thereby affecting the stability of the quality and precision of the oil damper.

Summary of the invention

The present application is directed to the technical problem of the unstable quality and accuracy of the existing hydraulic damper, and proposes a valve body assembly, a piston unit to which the valve body assembly is applied, and a hydraulic damper to which the piston unit is applied.

In order to achieve the above objectives, the technical solution adopted in the present application is:

A valve body assembly is disposed on a piston body of a hydraulic damper, including a valve cover, and a valve core movably sleeved inside the valve cover, an outer surface of the valve cover and the piston body Connecting, the valve cover is provided with a guiding hole, the valve core is sleeved in the guiding hole, the valve core is clearance-fitted with the guiding hole to close the oil passage; the valve core and the piston body are elastic Connecting, the end of the valve cover facing away from the guiding hole is provided with an unloading hole, and one end of the valve cover on which the guiding hole is disposed is further provided with a fluid hole, and the fluid hole communicates with the unloading hole; The valve core is further sleeved in the unloading hole, and an outer surface of the valve core is clearance-fitted with an inner surface of the unloading hole to flow oil.

Preferably, the valve core is further provided with an oil sealing portion that can cooperate with the valve cover to close the oil passage, the oil sealing portion is disposed under the valve cover, and the top surface of the oil sealing portion The bottom surface of the valve cover is attached.

Preferably, the valve core is further provided with a tapered portion, and the tapered portion is sleeved in the relief hole, and the tapered portion is clearance-fitted with the relief hole to flow oil.

Preferably, the valve cover is further provided with an oil storage chamber, and a top end of the oil storage chamber is respectively connected with the guiding hole and the fluid hole, and a bottom end of the oil storage chamber is in communication with the unloading hole.

Preferably, an end of the valve core facing away from the piston body is axially disposed with an orifice, and the opposite end of the valve core is axially disposed with a blind hole, and the throttle hole communicates with the blind hole.

The present application further provides a piston unit disposed in a hydraulic damper, including a piston body, the piston body being provided with the valve body assembly described above.

Preferably, the valve body assembly is axially disposed at the top and bottom of the piston body.

Preferably, the valve body assembly at the top of the piston body and the valve body assembly at the bottom of the piston body are axially staggered.

Preferably, the valve body assembly at the top of the piston body is circumferentially distributed on the top of the piston body; the valve body assembly at the bottom of the piston body is circumferentially distributed at the bottom of the piston body.

The present application further provides a hydraulic damper including a working cylinder in which a piston unit is disposed, and the piston unit is provided with a valve body assembly as described above.

Compared with the prior art, the advantages and positive effects of the present application are as follows:

1. The valve body assembly of the present application is provided with a fluid hole on the valve cover, and the oil above the piston body sequentially passes through the fluid hole and the discharge port to realize the unloading and damping functions, thereby avoiding the prior art. The effect of the geometrical tolerance between the valve cover and the valve core when machining the unloading port on the sidewall of the blind hole of the valve core ensures the precision of the fit between the valve cover and the valve core, thereby making the application The valve body assembly has consistent quality and precision.

2. The valve body assembly of the present application, the oil above the piston body flows through the passage between the relief hole and the valve core, the top surface of the oil sealing portion and the bottom surface of the valve cover When the passages are evenly flowed in the circumferential direction, the radial force generated by the oil on the valve core cancels each other, thereby avoiding local stress fatigue of the valve core, and further improving the valve of the present application. The quality and service life of the body components.

3. The valve body assembly of the present application, wherein the valve core is provided with a tapered portion, and a variable cross-sectional oil passage is formed between the outer surface of the tapered portion and the inner surface of the unloading hole, thereby avoiding the valve core The valve body assembly of the present application is gently unloaded even when the downward movement is performed, even if a large amount of oil is circulated therein, thereby further improving the quality stability and the valve body of the present application. The assembly meets the linear or linear requirements of damping force and unloading speed.

4. The valve body assembly of the present application, the valve cover is further provided with an oil storage chamber, and the oil storage chamber can buffer the impact of the oil on the outer surface of the tapered portion when the valve core moves downward. The quality stability of the valve body assembly of the present application is further improved.

5. The valve body assembly of the present application, the throttle hole is disposed at a top end of the valve core, and is not only easy to process, but also does not affect the valve core during processing, compared with the throttle hole of the prior art. The precision of the mating of the surface with the inner surface of the through hole.

DRAWINGS

Figure 1 is a plan view of a prior art piston unit;

Figure 2 is a cross-sectional view taken along line A-A of Figure 1;

3 is a schematic structural view of a piston unit according to an embodiment of the present application;

Figure 4 is a plan view of Figure 3;

Figure 5 is a cross-sectional view taken along line A-A of Figure 4 in an embodiment of the present application;

Figure 6 is a view showing a state of oil flow of the piston unit of Figure 5;

7 is a schematic structural view of a valve core according to an embodiment of the present application;

Figure 8 is a cross-sectional view taken along line A-A of Figure 4 in another embodiment of the present application;

Figure 9 is a view showing the oil flow state of the valve cover and the valve core of Figure 8;

10 is a schematic structural view of a valve cover according to an embodiment of the present application;

Figure 11 is a cross-sectional view 1 of a piston unit according to an embodiment of the present application;

Figure 12 is a cross-sectional view 2 of the piston unit according to an embodiment of the present application.

FIG. 13 is a schematic structural view of a hydraulic damper according to an embodiment of the present application.

In the figure: 1, piston unit; 11, piston body; 111, discharge port; 12, valve body assembly; 121, valve cover; 1211, through hole; 122, valve core; 1221, blind hole; 1222, unloading port; , sealing oil department; 1224, orifice; 123, spring;

2, piston unit; 21, piston body; 211, discharge port; 22, valve body assembly; 221, valve cover; 2211, guide hole; 2212, relief hole; 2213, fluid hole; 2214, oil storage chamber; Spool; 2221 Sealing oil part; 2222, taper part; 2223, orifice; 2224, blind hole; 223, spring; 3, oil pressure damper; 31, working cylinder.

Detailed ways

Hereinafter, the present application will be specifically described by way of exemplary embodiments. It should be understood, however, that the elements, structures, and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.

In the description of the present application, it should be noted that the axial direction refers to the axial direction of the working cylinder and the piston body, and also the direction in which the piston body moves; the circumferential direction refers to the circumferential direction of the working cylinder and the piston body; the radial direction refers to the work. The radial direction of the cylinder and the piston body; the orientation or positional relationship of the terms "top", "bottom", "inside", "outer", "upper", "lower", "front", "rear", etc. is based on the drawing 2 and the positional relationship shown in FIG. 3 is for the convenience of describing the present application and the simplified description, and does not indicate or imply that the device or component referred to has a specific orientation, is constructed and operated in a specific orientation, and therefore cannot be understood. To limit the application. Moreover, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

3 is a schematic structural view of the valve body assembly 22 and its upper piston unit 2 of the present application, FIG. 4 is a plan view of FIG. 3, and FIG. 5 is a cross-sectional view taken along line A-A of FIG. As shown in FIG. 3, a valve body assembly 22 is disposed on the piston body 21 of the hydraulic damper for closing or opening the oil passage to achieve a shock absorbing effect, and the hydraulic damper is filled with Oil. As shown in FIG. 5, the valve body assembly 22 of the present application includes a valve cover 221, a valve core 222, and a spring 223, and an outer surface of the valve cover 221 is screwed to the piston body 21, wherein the outer surface refers to a side of the cylindrical valve cover 221; the valve cover 221 is axially disposed with a guiding hole 2211 and an unloading hole 2212. The valve body 222 is sleeved in the guiding hole 2211 and the unloading hole 2212 from top to bottom. The outer surface of the upper portion of the valve core 222 is precisely clearance-fitted with the inner surface of the guiding hole 2211. The precision of the clearance fit satisfies the precise guiding function and can close the oil passage. The outer surface of the lower portion of the valve core 222 is The inner surface of the relief hole 2212 is clearance-fitted to form a passage through which the oil can pass; the valve cover 221 is further axially disposed with a fluid hole 2213, the top of the relief hole 2212 and the guide hole 2211 and the fluid, respectively The holes 2213 are in communication, and the oil above the piston body 21 can pass through the fluid The hole 2213 flows into the passage between the relief hole 2212 and the valve core 222; the bottom surface of the valve core 222 is elastically connected to the bottom surface of the piston body 21, that is, the bottom surface of the valve core 222 passes through the spring 223 and the The bottom surface of the piston body 21 is connected, and a bottom surface of the piston body 21 is provided with a discharge port 211 at a position corresponding to the valve body 222.

Fig. 6 is a view showing a state of oil flow on the side of the piston unit 2 when the piston body 21 shown in Fig. 5 is moved upward; the oil flow state on the other side is the same, and is omitted here. When the piston body 21 moves upward, when the hydraulic pressure above the piston body 21 forces the valve core 222 to move downward, the spring 223 will be compressed, and the fluid hole 2213 and the oil below the piston body 21 The liquid phase communicates such that the oil above the piston body 21 sequentially passes through the fluid hole 2213, the passage between the relief hole 2212 and the spool 222, and the discharge port 211 and the piston body 21 The oil and liquid phases are connected to realize the unloading and damping functions, and the flow direction of the oil is as indicated by the dotted arrow in FIG.

The valve body assembly 22 of the present application realizes the unloading and damping functions by providing the fluid hole 2213 and the relief hole 2212 on the valve cover 221, thereby avoiding the blind hole 1221 in the valve body 122 in the prior art. The influence of the geometrical tolerance between the valve cover 121 and the valve core 122 when the unloading port 1222 is processed on the side wall ensures the matching precision between the valve cover 121 and the valve core 122, thereby making the valve body of the present application Assembly 22 has consistent quality and precision performance.

In addition, the unloading port 1222 of the prior art is disposed on one side of the blind hole 1221 of the valve body 122, and the oil above the piston body 11 flows into the lower portion of the piston body 11 through the unloading port 1222. When the liquid flows through the unloading port 1222, a radial force is inevitably generated on the side wall of the valve body 122 on the opposite side of the unloading port 1222, thereby affecting the service life of the valve body 122; the valve body assembly of the present application 22, when the oil above the piston body 21 flows through the passage between the relief hole 2212 and the valve body 222, it flows uniformly in the circumferential direction, and the oil is applied to the valve body 222. The generated radial forces cancel each other out, avoiding local stress fatigue of the spool 222, further improving the quality and service life of the valve body assembly 22 of the present application.

As shown in FIG. 5 , the valve body 222 is further provided with an oil sealing portion 2221 , and the oil sealing portion 2221 is located below the valve cover 221 , and a top surface of the oil sealing portion 2221 and a bottom surface of the valve cover 221 . Adjacent The pre-tightening force of the spring 223 causes the top surface of the oil sealing portion 2221 to conform to the bottom surface of the valve cover 221, so that when the piston body 21 is stationary relative to the oil pressure damper, the The oil between the relief hole 2212 and the spool 222 is in fluid communication with the bottom of the spool 222.

Specifically, as shown in FIG. 5, in the initial position, the oil pressure above and below the piston body 21 is balanced, and the valve core 222 is sleeved in the guiding hole 2211 and the unloading hole 2212. A passage between the hole 2212 and the valve body 222 communicates with the oil in the oil body above the piston body 21 through the fluid hole 2213, and a top surface of the oil sealing portion 2221 is matched with a bottom surface of the valve cover 221 In order to close the oil passage; as shown in FIG. 6, when the piston body 21 moves upward, the oil pressure above the piston body 21 increases, and the oil hydraulic pressure above the piston body 21 forces the spool 222 and the spring. 223, moving the valve body 222 downward and compressing the spring 223, so that the top surface of the oil sealing portion 2221 is separated from the bottom surface of the valve cover 221, thereby opening the oil passage, that is, the The oil above the piston body 21 sequentially passes through the fluid hole 2213, the passage between the relief hole 2212 and the valve body 222, the top surface of the oil sealing portion 2221 and the bottom surface of the valve cover 221 The passage flows into the bottom of the spool 222 and finally flows into the piston body 21 through the discharge port 211. Below, the oil pressure above and below the piston body 21 is balanced to achieve an unloading and damping effect; when the piston body 21 stops moving, the restoring force of the spring 223 causes the spool 222 to upward The movement causes the top surface of the oil sealing portion 2221 to be brought into contact with the bottom surface of the valve cover 221 again, thereby closing the oil passage again.

As shown in FIG. 7, as a preferred embodiment, the valve body 222 is further provided with a tapered portion 2222. As shown in FIG. 8 , the tapered portion 2222 is sleeved in the relief hole 2212 , and an oil passage is formed between an outer surface of the tapered portion 2222 and an inner surface of the relief hole 2212 , and It communicates with the oil in the fluid hole 2213 so that the oil above the piston body 21 can flow. The tip end of the tapered portion 2222 faces the guide hole 2211. FIG. 9 is a view showing a state of oil flow in the valve cover 221 and the valve body 222 when the piston body 21 shown in FIG. 8 is moved upward, the piston body 21 is moved upward, so that the valve body 222 is Moving downwardly under the action of the upper oil pressure, the top surface of the oil sealing portion 2221 is separated from the bottom surface of the valve cover 221 to open the oil passage, and the outer surface of the tapered portion 2222 and the relief hole The area of the oil passage between the inner surfaces of the 2212 is gradually increased, thereby making the flow The amount of oil passing through is gradually increased, and the passage between the relief hole 2212 and the spool 222 is completely opened when the valve body 222 having no tapered portion shown in FIG. 6 is moved downward. In the case where the fluid flow amount is maximized and the momentary unloading is caused, in the present embodiment, the valve body assembly 22 which is realized by providing the tapered portion 2222 is unloaded smoothly, and the quality stability is further improved.

Further, as the spool 222 continues to move downward, the amount of compression of the spring 223 is increased, i.e., the valve body assembly of the present application produces a greater damping effect while the downward movement of the spool 222 The area of the oil passage between the outer surface of the tapered portion 2222 and the inner surface of the unloading hole 2212 is gradually increased, and the amount of oil flowing therethrough is gradually increased, so that the unloading speed is gradually increased, and the present application is made. The valve body assembly 22 meets linear or linear requirements for damping force and unloading speed.

Referring to FIG. 5, FIG. 6, FIG. 8, and FIG. 9, as a preferred embodiment, the valve cover 221 is further provided with an oil storage chamber 2214, and the oil storage chamber 2214 is located at the guiding hole 2211 and the relief hole. 2212, and the top end of the oil storage chamber 2214 communicates with the guiding hole 2211 and the fluid hole 2213, respectively, and the bottom end of the oil storage chamber 2214 communicates with the unloading hole 2212 due to the valve The precise clearance of the core 222 and the guiding hole 2211 can realize a precise guiding function and can close the oil passage. When the valve core 222 is sleeved in the guiding hole 2211 and the relief hole 2212, the piston body 21 The upper oil can communicate with the oil reservoir 2214 through the fluid hole 2213, and the oil reservoir 2214 can buffer the valve core 222 to move downwards to the outside of the tapered portion 2222. The impact of the surface further enhances the quality stability of the valve body assembly 22 of the present application.

Referring to FIG. 10, as a preferred embodiment, the fluid hole 2213 is disposed in a circumferential ring outside the circumference of the guiding hole 2211, and the fluid hole 2213 may be disposed in one or more to meet different unloading. And vibration damping requirements. Preferably, when the plurality of fluid holes 2213 are plural, the plurality of fluid holes 2213 are evenly distributed in the circumferential ring body outside the circumference of the guiding hole 2211 in order to make the oil flow uniform during the unloading process.

Referring to FIG. 5, FIG. 7, FIG. 8, and FIG. 9, as a preferred embodiment, an end of the valve core 222 facing away from the spring 223 is axially disposed with an orifice 2223, and the valve core 222 is opposite to the other. A blind hole 2224 is axially disposed at one end, and the throttle hole 2223 is in communication with the blind hole 2224. In other words, A blind hole 2224 is defined in the direction of the spring 223, and the throttle hole 2223 is opened at the bottom of the blind hole 2224. When the piston body 21 produces a slight upward movement, that is, the oil pressure above the piston body 21 is slightly increased, and the oil pressure is insufficient to overcome the spring force of the spring 223, above the piston body 21 The oil can flow into the blind hole 2224 through the orifice 2223, and flow into the lower portion of the piston body 21 through the discharge port 211 on the piston body 21, thereby achieving the unloading and damping effects.

It should be noted that, in the prior art, the bottom end of the blind hole 1221 of the valve body 122 is radially provided with an orifice 1224, and the throttle hole 1224 will be the blind hole 1221. The oil in the oil communicates with the oil under the piston body 11. When the piston body 11 produces a slight upward movement, the oil above the piston body 11 can pass through the blind hole 1221 and the orifice in sequence. 1224 flows into the lower portion of the piston body 11 to achieve unloading and damping effects. However, since the throttle hole 1224 is located at the bottom surface of the blind hole 1221, the processing is inconvenient, and when the throttle hole 1224 is processed, the valve core 122 needs to be clamped with the through hole 1211 of the valve cover 121. The mating outer surface inevitably affects the fitting precision of the outer surface of the valve body 122 and the inner surface of the through hole 1211.

The valve body assembly 22 of the present application is provided with an orifice 2223 at the top end of the valve body 222, through which the oil and liquid of the upper and lower portions of the piston body 21 are connected to each other through the orifice 2223 and the blind hole 2224. The throttle hole 2223 is disposed at the top end of the valve body 222, which is not only easy to process, but also needs to clamp the outermost surface of the bottom end of the valve body 222 when the throttle hole 2223 is processed. The surface is a non-mating surface, which in turn does not affect the fitting accuracy of the valve body assembly 22 of the present application, and further improves the stability of the quality and precision of the valve body assembly 22 of the present application.

In order to further improve the sealing performance of the valve body assembly 22 of the present application, the threaded seal of the valve cover 221 and the screw body of the piston body 21 is coated with a thread sealant to ensure the position of the valve cover 221 is stable after being installed in position, and The sealing performance of the thread pair is improved, and the quality stability of the valve body assembly 22 of the present application is further improved.

As shown in FIG. 3 and FIG. 4, the present application further provides a piston unit 2, which is disposed in a hydraulic damper, and includes a piston body 21, and the piston body 21 is provided with the valve body assembly 22 described above.

As a preferred embodiment, the valve body assembly 22 is axially disposed at the top and bottom of the piston body 21, and the valve body assembly 22 at the bottom of the piston body 21 and the valve body assembly at the top of the piston body 21 Deviate from each other.

Further, in order to smoothly realize the two-way unloading and damping function of the piston unit 2 of the present application, the valve body assembly 22 at the top of the piston body 21 and the valve body assembly 22 at the bottom of the piston body 21 are axially interlaced Settings.

As shown in FIG. 3, the valve body assembly 22 at the top of the piston body 21 can be provided in one or more to meet different vibration damping requirements. Preferably, when the valve body assembly 22 at the top of the piston body 21 is disposed in plurality, the plurality of valve body assemblies 22 are evenly distributed circumferentially on the top of the piston body 21 to increase the piston body 21 of the present application. The stability of the piston unit 2 during unloading and damping during upward movement.

Further, the valve body assembly 22 at the bottom of the piston body 21 may be provided in one or more to meet different vibration damping requirements. Preferably, when the valve body assembly 22 at the bottom of the piston body 21 is disposed in plurality, the plurality of valve body assemblies 22 are evenly distributed circumferentially at the bottom of the piston body 21 to increase the piston body 21 downward. During the movement, the piston unit 2 of the present application has stability during unloading and damping.

Hereinafter, the valve body assembly 22 at the top of the piston body 21 and the valve body assembly 22 at the bottom are staggered in the radial direction of the piston body 21, and the valve body 222 of the valve body assembly 22 is provided with a tapered portion 2222. For example, the operation of the piston unit 2 will be described. A cross-sectional view of the piston body 21 is shown in FIGS. 11 and 12.

As shown in FIG. 11, when the piston body 21 moves upward, the oil pressure above the piston body 21 increases and presses the spool 222 of the top valve body assembly 22 of the piston body 21 relative to the The piston body 21 descends and compresses the spring 223, so that the top surface of the oil sealing portion 2221 of the valve body 222 is separated from the bottom surface of the valve cover 221, as shown by the broken line in FIG. 11, the oil above the piston body 21 is sequentially Flowing through the fluid hole 2213, the oil reservoir 2214, the passage between the tapered portion 2222 and the relief hole 2212, the passage between the top surface of the oil seal portion 2221 and the bottom surface of the valve cover 221 The bottom of the 222 finally flows into the lower portion of the piston body 21 through the discharge port 211, thereby achieving an unloading and damping effect. One of the plurality of valve body assemblies 22 at the top of the piston body 21, one or more of the valve cores 222 The throttle hole 2223 is provided. When the upward movement of the piston body 21 causes the increase of the oil pressure above the piston body 21 to be insufficient to compress the spring 223, the oil above the piston body 21 sequentially passes through the orifice 2223 and A blind hole 2224 flows into the lower portion of the piston body 21 to achieve an unloading and damping effect. During this process, the valve body assembly 22 at the bottom of the piston body 21 does not function.

As shown in FIG. 12, when the piston body 21 moves downward, the oil pressure under the piston body 21 increases and presses the spool 222 of the valve body assembly 22 at the bottom of the piston body 21, so as to be opposite to the The piston body 21 rises and compresses the spring 223, so that the bottom surface of the oil sealing portion 2221 of the valve body 222 is separated from the top surface of the valve cover 221, as shown by the broken line in FIG. 12, the oil below the piston body 21 Passing through the fluid hole 2213, the oil reservoir 2214, the passage between the tapered portion 2222 and the relief hole 2212, the passage between the bottom surface of the oil seal portion 2221 and the top surface of the valve cover 221, flows into the valve. The upper portion of the core 222 finally flows into the upper portion of the piston body 21 through the discharge port 211, thereby achieving an unloading and damping effect. One of the plurality of valve body assemblies 22 at the bottom of the piston body 21 is provided with an orifice 2223 at the bottom of one or more of the valve bodies 222, and the oil pressure below the piston body 21 caused by the downward movement of the piston body 21 When the increase is insufficient to compress the spring 223, the oil below the piston body 21 sequentially flows into the piston body 21 through the orifice 2223 and the blind hole 2224 to achieve the unloading and damping effects. During this process, the valve body assembly 22 at the top of the piston body 21 does not function.

As shown in FIG. 13, the present application further proposes a hydraulic damper 3 including a working cylinder 31 in which the aforementioned piston unit 2 is disposed. It will not be described in detail here.

Claims (10)

A valve body assembly (22) is disposed on a piston body (21) of a hydraulic damper, including a valve cover (221), and a valve body movably sleeved inside the valve cover (221) ( 222), an outer surface of the valve cover (221) is connected to the piston body (21), the valve cover (221) is provided with a guiding hole (2211), and the valve core (222) is sleeved on the In the guiding hole (2211), the valve core (222) is clearance-fitted with the guiding hole (2211) to close the oil passage; the valve core (222) is elastically connected with the piston body (21), and is characterized in that An end of the valve cover (221) facing away from the guiding hole (2211) is provided with an unloading hole (2212), and one end of the valve cover (221) on which the guiding hole (2211) is disposed is further provided with a fluid hole (2213), the fluid hole (2213) is in communication with the unloading hole (2212); The valve core (222) is further sleeved in the relief hole (2212), and an outer surface of the valve core (222) is clearance-fitted with an inner surface of the relief hole (2212) to flow oil. The valve body assembly (22) according to claim 1, wherein said valve body (222) is further provided with an oil seal portion (2221) engageable with said valve cover (221) to close the oil passage. The oil sealing portion (2221) is disposed under the valve cover (221), and a top surface of the oil sealing portion (2221) is in contact with a bottom surface of the valve cover (221). The valve body assembly (22) according to claim 1, wherein the valve body (222) is further provided with a tapered portion (2222), and the tapered portion (2222) is sleeved on the unloading In the hole (2212), the tapered portion (2222) is clearance-fitted with the relief hole (2212) to circulate the oil. The valve body assembly (22) according to claim 3, wherein the valve cover (221) is further provided with an oil reservoir (2214), the top end of the oil reservoir (2214) and the guide respectively The hole (2211) is in communication with the fluid hole (2213), and the bottom end of the oil reservoir (2214) is in communication with the relief hole (2212). The valve body assembly (22) according to claim 1, wherein an end of the valve body (222) facing away from the piston body (21) is axially provided with an orifice (2223), the spool The opposite end of the (222) is axially provided with a blind hole (2224), and the throttle hole (2223) is in communication with the blind hole (2224). A piston unit (2), disposed in a hydraulic damper, comprising a piston body (21), wherein the piston body (21) is provided with the valve according to any one of claims 1-5 Body assembly (22). The piston unit (2) according to claim 6, characterized in that the valve body assembly (22) is axially disposed at the top and bottom of the piston body (21). The piston unit (2) according to claim 7, characterized in that the valve body assembly (22) at the top of the piston body (21) and the valve body assembly (22) at the bottom of the piston body (21) are at the shaft Staggered up each other. The piston unit (2) according to claim 8, wherein a valve body assembly (22) at the top of the piston body (21) is circumferentially distributed on top of the piston body (21); the piston A valve body assembly (22) at the bottom of the body (21) is circumferentially distributed at the bottom of the piston body (21). A hydraulic damper (3) comprising a working cylinder (31), characterized in that: a piston unit (2) is arranged in the working cylinder (31), and the piston unit (2) is provided with a claim The valve body assembly (22) of any of 1-5.

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