TWI866589B - Apparatus for burnishing process - Google Patents

Abstract

An apparatus for burnishing process includes an outer cover, a burnishing unit, a spring assembly unit, a sensor and an anti-overload unit. The burnishing unit is connected to the outer cover. The spring assembly unit, sensor and anti-overload unit are all installed inside the cover. The sensor is installed between the burnishing unit and the spring assembly unit to withstand the double-sided force induced from the burnishing unit and the spring assembly unit, thereby obtaining accurate burnishing force values. The anti-overload unit is used to limit the maximum distance of the spring assembly unit when it is compressed, to avoid the overload of the sensor. The anti-overload unit and the sensor are respectively installed at two opposite ends of the spring assembly unit, to avoid interfering with the extension and contraction movement of the spring assembly unit.

Description

Extrusion processing equipment

The present invention relates to an extrusion processing device, in particular to an extrusion processing device suitable for a CNC processing machine or a milling machine.

In the manufacturing industry, the surface roughness of the processed product is a major indicator for evaluating the quality of the finished product. For example, in processes such as plastic injection and blow molding, the surface roughness of the mold is a key factor affecting the quality of the finished plastic product. In order to improve the surface finish of the mold, grinding, lapping or polishing techniques are used to process the mold core and cavity. However, using these processing techniques not only takes a long time to process, but the grinding wheel and polishing ball are also easily worn, and the equipment required for processing is also expensive.

In addition to the aforementioned processing technologies, extrusion processing technology is another common chipless surface finishing technology. Proper control can reduce the surface roughness of metal cutting parts without changing the surface profile. In the extrusion operation, when the extrusion tool is used to apply a load to the surface of the workpiece and press down to make contact, the extrusion force (also called "extrusion force") generated will cause the workpiece to produce plastic deformation, thereby improving the surface roughness and surface hardness of the workpiece. Extrusion components usually use harder materials, so they are not easy to wear. They are very suitable for a larger range of finishing operations, and the required surface finishing operation time can also be shortened. Since the extrusion force is one of the important factors affecting the processing accuracy, how to know the extrusion force exerted on the extrusion component is an important topic.

Most of the extrusion devices used in previous research literature and the extrusion tool products on the market are suitable for two-axis lathes, but not for milling machines with more than three axes. A few extrusion tools suitable for milling machines, such as Patent No. I344886 of the Republic of China, use built-in sensors to measure the extrusion force.

However, the elastic element and the extrusion element in this patent document are installed on the same side of the sensor. The reaction force between the extrusion element and the workpiece will be affected by the elastic force of the elastic element during the process of being transmitted to the sensor, making the extrusion force measured by the sensor inaccurate.

The safety device in this patent document is installed in the guide groove on the side of the sleeve, and the maximum deformation of the elastic element is limited by the guide groove stroke, thereby limiting the maximum force of the sensor to avoid overload. Therefore, its spring must be selected in conjunction with the safety device, which is more restricted. This installation method of the safety device is prone to interfere with the spring installed inside the sleeve, causing the overall mechanism of the extrusion tool to operate unsmoothly. In addition, the guide groove structure of the sleeve will also make it difficult to shorten the overall length of the extrusion device.

In view of this, the inventor of this case improved the known extrusion tool to solve the above-mentioned problems such as inaccurate extrusion force measurement and safety devices causing the extrusion tool to operate unsmoothly.

One purpose of the present invention is to provide an extrusion processing device suitable for a milling machine and capable of measuring a more accurate extrusion force during operation.

Another purpose of the present invention is to provide an extrusion processing device whose overload protection mechanism will not cause the extrusion processing device to operate unsmoothly.

In order to achieve the above-mentioned purpose, the present invention provides an extrusion processing device, including an outer cover, an extrusion unit, an elastic unit, a sensor and an anti-overload unit. The extrusion unit is connected to the outer cover. The elastic unit, the sensor and the anti-overload unit are all installed inside the outer cover. The sensor is installed between the extrusion unit and the elastic unit to withstand the double-sided pressure from the extrusion unit and the elastic unit, thereby obtaining an accurate extrusion force value. The anti-overload unit is used to limit the maximum compression stroke of the elastic unit to avoid overloading the sensor. In addition, the anti-overload unit and the sensor are respectively installed at two opposite ends of the elastic unit to avoid interfering with the extension and contraction movement of the elastic unit.

In one embodiment, the extrusion processing device further includes a pad installed between the extrusion unit and the sensor to prevent the sensor from being directly hit by the extrusion unit.

In one embodiment, the elastic unit includes an assembly of a spring, a spring top plate and a spring bottom plate, wherein the spring is installed between the spring top plate and the spring bottom plate.

In one embodiment, the sensor is a load cell mounted between the spring base and the pad.

In one embodiment, the extrusion processing device further includes a base installed inside the outer cover, wherein the elastic unit, the load cell and the pad are all installed inside the base.

In one embodiment, the overload protection unit includes at least one safety screw which is locked to the spring top plate, one end of the safety screw passes through the spring top plate and maintains a distance with the base, so that the maximum compression stroke of the spring is limited by this distance, thereby preventing the load cell from exceeding the load.

In one embodiment, the extrusion processing device further includes a preload adjustment screw, which is locked to the outer cover and abuts against the spring top plate to adjust the initial preload of the spring.

In one embodiment, the extrusion unit includes a processing element, a sleeve, a handle and a handle positioning screw, and the sleeve includes a lock, wherein after the processing element passes through the sleeve, the sleeve is locked to the handle with the lock; the handle is fixed in the base by the handle positioning screw.

In one embodiment, the processing element is selected from an extrusion rod, an extrusion ball and a push rod.

In the extrusion processing device of the present invention, the reaction force between the processing element and the workpiece does not pass through the elastic unit before being transmitted to the sensor, so the extrusion force measured by the sensor will not be inaccurately measured due to the addition or cancellation of the reaction force by the elastic force of the spring. In addition, the anti-overload unit is installed at one end of the elastic unit instead of on the side of the elastic unit, which can make the overall operation of the extrusion processing device smoother.

The other technical contents, features and effects of the present invention mentioned above will be clearly presented in the following detailed description of a preferred embodiment with reference to one of the drawings.

FIG1 is a schematic diagram of an extrusion processing device according to an embodiment of the present invention. The extrusion processing device 100 is suitable for installation on a three-axis or five-axis computer numerical control (CNC) machining center or milling machine, and can perform a surface extrusion finishing process on a workpiece after cutting. The extrusion processing device 100 includes a pre-stress adjustment screw 110, an outer cover 120, an overload protection unit 130, an elastic unit 140, a sensor 150, a base 160, a pad 170, and an extrusion unit 180. The outer cover 120 has a bottom fixing plate 122 and a plurality of outer cover locking screws 124, and the outer cover locking screws 124 are used to fix the bottom fixing plate 122 to the bottom of the outer cover 120. The elastic unit 140 is an assembly of a spring 142, a spring top plate 144 and a spring bottom plate 146. The extrusion unit 180 includes a processing element 182, a sleeve 184, a handle 186 and a handle positioning screw 188, and the sleeve 184 includes a lock head 185.

FIG2 is a side view schematic diagram of an extrusion processing device of an embodiment of the present invention, and the extrusion processing device is obtained by assembling the various components shown in FIG1. FIG3 is a B-B cross-sectional schematic diagram of the extrusion processing device of FIG2. When assembled, the pre-stress adjustment screw 110, the overload protection unit 130, the elastic unit 140, the sensor 150, the base 160 and the pad 170 are all installed inside the outer cover 120. The elastic unit 140 is composed of a spring 142 installed between a spring top plate 144 and a spring bottom plate 146. It is worth noting that the sensor 150 must be located between the extrusion unit 180 and the elastic unit 140, and more specifically, between the spring base plate 146 and the pad 170, so that the two opposite sides of the sensor 150 can bear the double-sided pressure from the extrusion unit 180 and the elastic unit 140, respectively, thereby obtaining an accurate extrusion force value. The anti-overload unit 130 and the sensor 150 are respectively installed at two opposite ends of the elastic unit 140, so that when the elastic unit 140 performs extension and contraction movements, there will be less interference, so that the overall operation of the extrusion processing device 100 is smoother. The extrusion unit 180 is composed of a processing element 182 that first passes through a sleeve 184, and then uses a lock 185 to lock the sleeve 184 to a handle 186. When in use, the extrusion unit 180 is installed on the outside of the outer cover 120, and its handle 186 is detachably connected to the outer cover 120.

Taking a more specific example, the structure and function of each component are described as follows.

The outer cover 120 has a clamping end 121 located above it. The clamping end 121 has a pipe 123 inside, and its outer diameter is, for example, 25 mm, which is suitable for installation on standard CNC milling machines produced by various manufacturers in the market. The outer cover 120 includes a accommodating space 125 inside that is connected to the pipe 123 above it. The pre-stress adjustment screw 110 is locked into the through hole at the top of the outer cover 120, locked to the outer cover 120 through the pipe 123, and abuts against the spring top plate 144. The pre-stress adjustment screw 110 is rotated to adjust its locking depth, thereby controlling the initial length or initial pre-stress of the spring 142, that is, adjusting the initial pre-stress provided by the elastic unit 140 to the extrusion unit 180. The overload protection unit 130, the elastic unit 140, the sensor 150, the base 160, and the pad 170 are all installed in the accommodation space 125 of the outer cover 120.

The base 160 is the center of the whole mechanism, which is installed inside the outer cover 120. The base 160 can be locked to the bottom fixing plate 122 by the outer cover locking screw 124. The spring bottom plate 146 of the elastic unit 140, the sensor 150 and the gasket 170 are all installed in the inner space of the base 160. The handle 186 of the extrusion unit 180 passes through the bottom fixing plate 122 of the outer cover 120 to keep it vertically movable, so that the handle 186 and the base 160 are tightly matched, and the handle positioning screw 188 is used to fix the handle 186 and the gasket 170 in the base 160 to prevent rotation during the processing process. The pad 170 is installed between the extrusion unit 180 and the sensor 150 to prevent the sensor 150 from being directly hit by the extrusion unit 180. The processing element 182 can be replaced by sliding, rolling or different shapes and materials, such as: extrusion rods, extrusion balls or push rods, etc., and the material can be tungsten carbide. In one embodiment, the extrusion unit 180 can be locked by the ER-25 standardized tool elastic sleeve and the processed ST25 standardized tool holder, so the suitable processing element 182 can be replaced according to the processing environment.

The elastic force generated by the elastic unit 140 after compression can provide the extrusion force required for the extrusion process. In addition, the elastic unit 140 can eliminate the positioning error when the extrusion unit 180 moves along the free surface path, reduce the external interference factors such as the machine tool vibration during the extrusion process, improve the processing stability, and reduce the adhesion caused by friction between the processing element 182 and the workpiece (not shown), thereby protecting the working surface. In one embodiment, the spring 142 of different stiffness can be replaced when using different extrusion forces for processing, so as to obtain appropriate force feedback on the CNC machine (not shown) that controls the stroke to enhance the flexibility of the operation.

The sensor 150 is, for example, a load meter 150A. Since a general load meter 150A has a maximum load value, an overload protection unit 130 is designed to prevent the load meter 150A from being overloaded and damaged. The upper surface of the load meter 150A contacts the spring bottom plate 146, and there is a hole below the contact surface between the load meter 150A and the base 160 for setting the pad 170, so that the bottom surface of the load meter 150A can contact the pad 170. The load meter 150A can be inserted into the base 160 through the side slot of the base 160, and the transmission line is guided to a Bluetooth transmission module to cooperate with the program to transmit the extrusion force value in real time to the personal computer display.

The anti-overload unit 130 is used to limit the maximum compression stroke of the elastic unit 140, thereby limiting the maximum force of the sensor 150 to avoid overload. In one embodiment, the anti-overload unit 130 includes a plurality of safety screws 130A that are locked to the spring top plate 144 and are arranged in a ring around the spring 142. As shown in FIG3, the nut of the safety screw 130A is located above the spring top plate 144, and the lower end of the safety screw 130A passes through the spring top plate 144 and maintains a distance D with the top surface of the base 160 under no load, so that the maximum compression stroke of the spring 142 is limited by the distance D. When the compression stroke of the elastic unit 140 is too large, an excessive squeezing force will be generated, thereby causing damage to the load cell 150A. Therefore, by selecting or adjusting the length L of the safety screw 130A, the distance D between the safety screw 130A and the base 160 can be adjusted, thereby limiting the maximum compression stroke of the elastic unit 140 to prevent the load cell 150A from exceeding the load. It can be understood that the safety screw 130A, the elastic unit 140 and the base 160 of the present embodiment together form a mechanism to prevent the sensor 150 from being overloaded. Compared with the prior art, the anti-overload unit 130 of this embodiment is installed at one end of the elastic unit 140 instead of being inserted horizontally from the side of the spring 142, which can make the overall operation of the extrusion processing device 100 smoother.

During the processing operation, the top of the outer cover 120 can be installed in a tool handle (not shown) and a sleeve (not shown) generally applicable to a milling machine so as to be locked in a CNC machining center (not shown). The CNC machining center controls the Z-axis stroke to adjust the height of the extrusion processing device. When contacting the workpiece (not shown), the tip of the extrusion rod 182A first contacts the workpiece (not shown). At this time, the machine tool continues to press down, so that the reaction force between the extrusion rod 182A and the workpiece (not shown) is transmitted all the way upward to the pad 170, the load meter 150A, the spring bottom plate 146, the spring 142, the spring top plate 144, and the preload locked in the outer cover 120. Adjust the screw 110; at this time, the spring 142 is compressed by force, and the degree of compression depends on the elastic coefficient used and the Z-axis travel. The elastic force of the spring 142 after being compressed is transmitted downward to the spring base plate 146 and the load gauge 150A; the upper and lower sides of the load gauge 150A are respectively subjected to double-sided pressure from the original reaction force and the rebound force of the spring 142, and the total pressure borne is the accurate extrusion force value. Therefore, the required extrusion force can be accurately monitored by the elastic coefficient of the spring 142 and the load gauge 150A.

It is worth emphasizing that the reaction force between the extrusion rod 182A and the workpiece (not shown) of this embodiment does not pass through the elastic unit 140 before being transmitted to the load cell 150A. Therefore, the extrusion force measured by the load cell 150A will not be inaccurately measured due to the addition or cancellation of the reaction force by the elastic force of the spring 142.

In the case of overload, the safety screw 130A contacts the base 160 due to the downward pressure stroke X (indicated by the dotted arrow in Figure 3) of the spring top plate 144. At this time, the force is not transmitted through the spring 142 and the load meter 150A, but directly transmitted to the base 160 by the safety screw 130A, so that the base 160 replaces the load meter 150A to bear the force, thereby preventing the load meter 150A from being damaged. The maximum compression stroke of the spring 142 can be calculated according to the overload value of different load meters 150A, and the safety screw 130A of appropriate length can be selected to limit the maximum compression stroke of the spring 142, so as to protect the load meter 150A.

In summary, the present invention can be applied to milling machines and can measure more accurate extrusion force during operation, and its overload protection mechanism will not cause the extrusion processing device to operate unsmoothly. In addition, the present invention also has the following features:

1. The overall length is shorter and the weight is lighter than that of known extrusion tools.

2. Appropriate springs, safety screws and pre-stress adjustment screws can be replaced according to different workpieces.

3. The spring provides the function of absorbing vibration, reducing positioning errors, and protecting the machine tool spindle from impact and reducing life.

4. The safety screw and the handle positioning screw suppress the rotation and shaking of the extrusion processing device, improving the processing stability.

5. Load meter with Bluetooth transmission function can be used with personal computer program to monitor and record the changes of extrusion force value in real time.

6. The outer cover of the extrusion processing device is suitable for installation on standard CNC milling machines produced by various manufacturers in the market.

7. The processing element at the front end of the extrusion unit can be used with an elastic collet to replace extrusion rods or extrusion balls of different sizes and materials.

However, the above is only the preferred embodiment of the present invention, and it cannot be used to limit the scope of the implementation of the present invention. That is, all simple equivalent changes and modifications made according to the scope of the patent application and the content of the invention description of the present invention are still within the scope of the present invention. In addition, any embodiment or patent application scope of the present invention does not need to achieve all the purposes, advantages or features disclosed by the present invention. In addition, the abstract part and the title are only used to assist the search of patent documents, and are not used to limit the scope of rights of the present invention.

100: Extrusion processing device

110: Pre-pressure adjustment screw

120: Outer cover

121: Clamping end

122: Bottom fixing plate

123: Pipeline

124: Cover locking screw

125: Storage space

130: Anti-overload unit

130A: Safety screw

140: Elastic unit

142: Spring

144: Spring top plate

146: Spring base plate

150:Sensor

150A: Load meter

160: Base

170: Pad

180: Extrusion unit

182: Processing components

182A: Squeezing rod

184: Sleeve

185: Lock

186: handle

188: Shank positioning screw

B-B: Section

D: Distance (between the safety screw and the base)

L: length (of safety screw)

X: Pressing stroke

Figure 1 is a schematic diagram of an exploded view of an extrusion processing device of one embodiment of the present invention.

Figure 2 is a side view schematic diagram of an extrusion processing device of one embodiment of the present invention.

Figure 3 is a cross-sectional schematic diagram of an extrusion processing device of one embodiment of the present invention.

100: Extrusion processing device

110: Pre-pressure adjustment screw

120: Outer cover

122: Bottom fixing plate

124: Cover locking screw

130: Anti-overload unit

140: Elastic unit

142: Spring

144: Spring top plate

146: Spring base plate

150:Sensor

160: Base

170: Pad

180: Extrusion unit

182: Processing components

184: Sleeve

186: handle

188: Shank positioning screw

185: Lock

Claims (8)

An extrusion processing device includes: an outer cover; a base installed inside the outer cover; an extrusion unit connected to the outer cover; an elastic unit installed inside the outer cover, wherein the elastic unit includes an assembly of a spring, a spring top plate and a spring bottom plate, wherein the spring is installed between the spring top plate and the spring bottom plate; a sensor installed inside the outer cover and installed between the extrusion unit and the elastic unit. and an anti-overload unit installed inside the outer cover, wherein the anti-overload unit and the sensor are installed at two opposite ends of the elastic unit respectively, and the anti-overload unit includes at least one safety screw which is locked to the spring top plate, wherein one end of the safety screw passes through the spring top plate and maintains a distance with the top surface of the base, so that the distance is equal to or less than the maximum compression stroke of the spring. The extrusion processing device as described in claim 1 further includes a pad installed between the extrusion unit and the sensor. The extrusion processing device as described in claim 2, wherein the sensor is a load cell installed between the spring base plate and the pad. The extrusion processing device as described in claim 3, wherein the elastic unit, the load cell and the pad are all installed inside the base. The extrusion processing device as described in claim 4 further includes a pre-stress adjustment screw that is locked to the outer cover and abuts against the spring top plate. The extrusion processing device as described in claim 1, wherein the extrusion unit includes a processing element, a sleeve and a handle, and the sleeve includes a lock, wherein after the processing element passes through the sleeve, the sleeve is locked to the handle with the lock. The extrusion processing device as described in claim 6, wherein the extrusion unit includes a handle positioning screw for fixing the handle in the base. The extrusion processing device as described in claim 6, wherein the processing element is selected from the group consisting of an extrusion rod, an extrusion ball and a push rod.

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