JP2019193958A - Vacuum chuck and auto-valve for vacuum chuck - Google Patents

Abstract

To provide an auto-valve for a vacuum chuck capable of stably fixing an object without deforming a fixing object.SOLUTION: A auto-valve comprises: a piston 12 slidable along a cylindrical shaft in a cylindrical space by partitioning a cylindrical space of a cylinder 11 into a first space 17 and a second space 18 in the cylindrical shaft direction; a third space 20 communicating with a vacuum pressure generation device; a first through-hole 8 penetrating through a suction base 2 up to the first space from an opening in a suction surface 3; a second through-hole 21 capable of maintaining an atmospheric pressure difference between the first space and the second space by penetrating between the first space and the second space; a third through-hole 19 penetrating between the second space and the third space; a valve element 12b provided in the piston and closing the third through-hole by sliding the piston by the atmospheric pressure difference between the first space and the second space; an energization member 24 for energizing the valve element in the direction for opening the third through-hole; and groove parts 14 and 15 communicating with the first through-hole and having an opening of extending along the suction surface.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a vacuum chuck and a vacuum chuck auto-valve for sucking and fixing an object placed on a suction surface.

  2. Description of the Related Art Conventionally, there is known a vacuum chuck that sucks and fixes an object placed on a suction surface through an opening that communicates with a flow path serving as a vacuum pressure. The vacuum chuck provides versatility corresponding to objects of various sizes by providing a plurality of openings, but air leaks from openings that are not blocked by the object among the plurality of openings. In order to prevent this, it was necessary to cover the opening with a masking tape. In this case, there is a problem that the processing is complicated because the masking tape is applied or peeled off depending on the object.

  On the other hand, the vacuum suction device described in Patent Document 1 includes a plurality of suction units, and a suction unit that is not blocked by an object out of the plurality of suction units sucks up an internal sphere and blocks the flow path. Thus, a structure that does not require a masking tape is disclosed.

  Further, in the vacuum chuck table described in Patent Document 2, the poppet is caused by a pressure difference between the atmospheric pressure applied to the top surface of the poppet head located at the opening on the suction surface of the valve and the pressure in the vacuum chamber that is reduced by sucking air. A structure is disclosed in which the masking tape is not required by pushing down against the biasing force of the spring and closing the flow path with a gasket provided on the poppet.

Japanese Patent No. 4892035 Japanese Utility Model Publication No. 52-15082

  However, in the vacuum suction device described in Patent Document 1, the configuration for closing the flow path is complicated, and when the vacuum is not sucked, the sphere is dropped by its own weight to open the flow path. Depending on the orientation of the sphere, the position of the sphere may not be stable, and the flow path should be opened, but it may remain in a closed state.

  Further, in the vacuum chuck table described in Patent Document 2, the diameter of the opening of the valve 17 on the suction surface is made larger than the diameter of the top surface of the head of the poppet 18 and the air pressure in the vacuum chamber is sucked when the air in the vacuum chamber is sucked. Is configured to be smaller than atmospheric pressure. In this way, when the diameter of the valve opening on the suction surface is large, when a thin object is fixed, the object is deformed so as to be recessed toward the center of the opening, and the processing on the fixed object is accurately performed. There was a problem that could not be done.

  Further, in the vacuum chuck table described in Patent Document 2, when air in the vacuum chamber 15 is sucked in a state where the object (workpiece 25) is placed on the valve plate 14, the object is once removed from the valve plate. After that, if there is a gap between the object and the valve plate 14, depending on the size of the gap, air enters through the gap and gradually the object and the poppet 18. There is a problem in that air accumulates in the space between the head and the poppet 18 and pushes down the poppet 18, eventually closing the gap between the gasket 19 and the stepped portion of the suction hole 16 and releasing the suction state. there were. Since the flatness of the object is not necessarily high, there are many cases where there is a gap between the object and the valve plate 14, and such a defect has occurred.

  The present invention has been made to solve the above-described problems, and a vacuum chuck capable of stably fixing an object regardless of the installation posture without deforming the fixed object and An object is to provide an auto valve for a vacuum chuck.

In order to solve the above-mentioned problems, the present invention is an auto valve for a vacuum chuck, comprising a suction base having a suction surface for sucking an object, a cylinder provided inside the suction base, and a cylinder of the cylinder Partitioning the space into a first space and a second space in a cylindrical axis direction, a piston slidable along the cylindrical axis in the cylindrical space, a third space communicating with a vacuum pressure generator, and A first through hole penetrating the suction base from an opening in the suction surface to the first space, and passing between the first space and the second space, the first space and the first space A second through hole capable of maintaining a pressure difference from the second space, a third through hole penetrating between the second space and the third space, the piston, The piston is caused by the pressure difference between the first space and the second space. A valve body that closes the third through hole by moving, a biasing member that biases the valve body in a direction to open the third through hole, and a suction member that communicates with the first through hole. And a groove having an opening extending along the surface.
ADVANTAGE OF THE INVENTION According to this invention, the auto valve for vacuum chucks which can fix a target stably without changing a fixed target and irrespective of an installation attitude | position can be provided.
According to the present invention, the object placed on the adsorption surface is adsorbed by the opening of the first through hole and the groove portion, and therefore the object is adsorbed only by the first through hole without deforming the object. Can be stably adsorbed with a stronger adsorbing force.

The present invention is also an auto valve for a vacuum chuck, wherein when an object closes an opening in the suction surface of the first through hole and the groove, the first space, the second space, and the first A closed space is formed with the third space, and an object is adsorbed on the adsorption surface by sucking air from the third space by the vacuum pressure generator.
According to the present invention, the air is sucked by the vacuum pressure generating device, so that the first through hole is not deformed by the opening of the first through hole and the groove without deforming the object placed on the suction surface. It can be stably adsorbed with a stronger adsorbing force than in the case of adsorbing only with pores.

Further, the present invention is an auto valve for a vacuum chuck, wherein when the first through hole and the opening of the groove portion on the suction surface are opened, air is supplied from the third space by the vacuum pressure generator. The piston slides due to a pressure difference between the first space and the second space due to suction, and the valve body closes the third through hole against a biasing force by the biasing member. It is characterized by that.
According to the present invention, the valve body closes the third through hole due to the pressure difference between the first space and the second space, and then the valve body is moved to the third position by the suction force that sucks air by the vacuum pressure generator. Since the third through hole is not opened and the object is not placed on the suction surface, air flow leakage during suction by the vacuum pressure generator is maintained. Will not occur.

Further, the present invention is an auto valve for a vacuum chuck, wherein an inner diameter of the first through hole is smaller than an inner diameter of the cylinder.
According to the present invention, by making the inner diameter of the first through hole smaller than the inner diameter of the cylinder, it is possible to suppress the deformation of the object during suction.

Further, the present invention is an auto valve for a vacuum chuck, wherein the groove portion includes a closed outer groove portion that continuously surrounds the opening of the first through hole in the suction surface, the outer groove portion, and the first groove portion. A communication groove portion that communicates with the through hole, and the suction surface includes an object support portion that supports an object between the first through hole and the outer groove portion. To do.
According to the present invention, the object supported by the object support unit is supported so as not to be deformed, and is adsorbed only by the first through hole by the communication groove part and the outer groove part. Can be adsorbed stably with a strong adsorption force.

Further, the present invention is an auto valve for a vacuum chuck, wherein the outer groove portion has a circular shape having a diameter larger than the inner diameter of the cylinder.
According to the present invention, the object placed on the suction surface can be more strongly adsorbed by forming the outer groove portion into a circular shape having a diameter larger than the cylinder inner diameter.

In addition, the present invention is an auto valve for a vacuum chuck, wherein the diameter of at least a part (throttle portion) of the second through hole is smaller than the diameter of the first through hole.
According to the present invention, it is possible to maintain a pressure difference between the first space and the second space by the throttle portion, and the third through hole is closed by the valve body due to the pressure difference, and the object is placed on the suction surface. Even if it is not done, there will be no leakage of airflow during suction by the vacuum pressure generator.

The present invention is also an auto valve for a vacuum chuck, wherein the second through hole is a gap between an outer periphery of the piston and an inner periphery of the cylinder.
According to the present invention, it is possible to easily form the second through hole.

Further, the present invention is an auto valve for a vacuum chuck, wherein the second through hole is a groove provided on an outer periphery of the piston.
According to the present invention, it is possible to easily form the second through hole.

Further, the present invention is a vacuum chuck, wherein the suction base includes a plurality of the vacuum chuck auto valves.
ADVANTAGE OF THE INVENTION According to this invention, the vacuum chuck which can fix a target object stably irrespective of direction can be provided, without deform | transforming a target object.

According to the present invention, it is possible to provide a vacuum chuck and a vacuum chuck auto-valve that can stably fix an object regardless of its orientation without deforming the fixed object.
Problems, configurations, and effects other than those described above will become apparent from the following description of embodiments.

It is a perspective view which shows the vacuum chuck which concerns on Example 1 of this invention. It is a perspective view which shows the state which mounted the target object 7 on the suction surface 3 of the vacuum chuck 1 shown in FIG. 2A and 2B are diagrams illustrating the auto valve 10 illustrated in FIG. 1, in which FIG. 1A is a plan view of the auto valve 10 viewed from the suction surface 3 side, and FIG. It is a figure explaining operation | movement of the auto valve 10 under the position in which the target object 7 was mounted, and is a sectional side view of the auto valve. It is a figure explaining operation | movement of the auto valve 10 of the position which remove | deviated from the position in which the target object 7 was mounted, Comprising: (a) is a sectional side view of the auto valve 10, (b) is (a). It is the top view which looked at piston 12 from the top. It is a sectional side view which shows the structure of the auto valve which concerns on Example 2 of this invention. It is the top view which looked at the vacuum chuck which concerns on Example 3 of this invention from the top. It is a figure which shows the structure of the piston which concerns on Example 4 of this invention, Comprising: (a) is the top view which looked at the piston from the top, (b) is a perspective view of a piston. It is a figure which shows the structure of the piston which concerns on Example 5 of this invention, Comprising: (a) is the top view which looked at the piston from the top, (b) is a perspective view of a piston. It is a figure which shows the auto valve which concerns on Example 6 of this invention, (a) is the top view which looked at the auto valve from the adsorption surface side, (b) is a sectional side view of an auto valve.

  Hereinafter, a vacuum chuck and an auto valve for a vacuum chuck according to the present invention will be described in detail with reference to the drawings. In the following drawings, in order to make each configuration easy to understand, the actual structure may be different from the scale and number in each structure.

(Structure of vacuum chuck 1)
FIG. 1 is a perspective view showing a vacuum chuck according to Embodiment 1 of the present invention. The vacuum chuck 1 sucks and fixes an object placed on the suction surface 3, for example, a workpiece that needs to be fixed during processing. The vacuum chuck 1 includes an adsorption base 2 having an adsorption surface 3, a pressure distribution plate 4 arranged so as to overlap the adsorption base 2, and a plurality of auto valves 10 arranged inside the adsorption base 2. Configured. As will be described in detail later, the auto valve 10 has a first through hole 8 (see FIG. 3A) having an opening in the suction surface 3.

  The pressure distribution plate 4 includes a valve 6, and a flow path 20 (see FIG. 3B) as a third space connected to one end of the pipe 5 through the valve 6. The other end of the pipe 5 is connected to a vacuum pressure generator (for example, a vacuum pump or an ejector that blows in compressed air from a compressor to generate negative pressure). By sucking air with this vacuum pressure generator, the object 7 (see FIG. 2) placed on the suction surface 3 is sucked and fixed. The flow path 20 communicates with all of the plurality of auto valves 10 provided in the vacuum chuck 1. For this reason, all the auto valves 10 can be operated only by sucking air through one pipe 5.

  FIG. 2 is a perspective view showing a state in which the object 7 is placed on the suction surface 3 of the vacuum chuck 1 shown in FIG. As shown in FIG. 2, the plurality of auto valves 10 may be located below the object 7, or may be located away from the object 7. Hereinafter, the configuration and operation of the auto valve 10 will be described in detail.

(Structure of auto valve 10)
3 is a view showing the auto valve 10 shown in FIG. 1. FIG. 3 (a) is a plan view of the auto valve 10 as viewed from the suction surface 3, and FIG. 3 (b) is a side sectional view of the auto valve 10. FIG. As shown in FIG. 3B, the suction base 2 has a cylindrical hollow portion 2a extending from the pressure distribution plate 4 side to the suction surface 3 side. The cylindrical hollow portion 2 a has a large diameter on the pressure distribution plate 4 side and a small diameter on the suction surface 3 side, and the diameter changes stepwise and extends in a direction perpendicular to the suction surface 3. Moreover, the cylindrical hollow part 2a has a circular cross-sectional shape in a direction parallel to the suction surface 3.

  The cylinder 11 is fastened with screws by fitting the flange portion of the cylinder 11 into the large diameter position of the cylindrical hollow portion 2a. The first through hole 8 is a hole at a small diameter position of the cylindrical hollow portion 2 a and is a through hole penetrating from the large diameter position of the cylindrical hollow portion 2 a to the suction surface 3. The cylinder 11 has a cylindrical shape, and the piston 12 is accommodated in the cylinder. The piston 12 includes a large diameter portion 12a disposed on the suction surface 3 side and a small diameter portion 12b disposed on the pressure distribution plate 4 side. The inner diameter of the first through hole 8 is smaller than the inner diameter of the cylinder 11.

  A ring seal 23 is provided on the outer peripheral surface of the large diameter portion 12 a of the piston 12. By this ring seal 23, airtightness between the outer peripheral surface of the large diameter portion 12a and the inner peripheral surface of the cylinder 11 is maintained. The ring seal 23 is an annular member, and as the material thereof, a fluorine resin or the like having high airtightness and low friction characteristics can be used. The piston 12 has a second through hole 21 penetrating from the end surface 12c on the suction surface 3 side of the large diameter portion 12a to the end surface 12d on the pressure distribution plate 4 side of the large diameter portion 12a. The 2nd through-hole 21 has the narrowing part 22 in the flow path. The diameter of at least a part of the second through hole 21 (throttle portion 22) is smaller than the diameter of the first through hole 8. The position where the narrowed portion 22 is provided is on the side close to the end face 12d between the end face 12c and the end face 12d. In consideration of ease of processing when manufacturing the piston 12, the position where the throttle portion 22 is provided may be on the side close to the end face 12c.

  A ring packing 25 is provided on the end surface 26 of the small diameter portion 12b of the piston 12 on the pressure distribution plate 4 side. When the piston 12 slides and the ring packing 25 comes into contact with the end face of the valve seat 13 on the suction face 3 side, the end face 26 and the valve seat 13 are sucked by the ring packing 25 provided on the small-diameter portion 12b as the valve body. The space between the end surface on the surface 3 side is closed, and the airtightness between the second space 18 and the third through hole 19 is maintained. The ring packing 25 is an annular member, and as the material thereof, a highly airtight fluororesin or the like can be used. A coil spring 24 as an urging member is provided on the outer periphery of the small diameter portion 12 b of the piston 12. The end of the coil spring 24 on the suction surface 3 side is in contact with the end surface 12d.

  An annular valve seat 13 is disposed at the end of the cylinder 11 on the pressure distribution plate 4 side. A male screw is provided on the outer periphery of the valve seat 13, and a female screw is provided at a position on the inner periphery of the cylinder 11 where the valve seat 13 is disposed. The valve seat 13 is fixed to the cylinder 11 by being screwed by the male screw and the female screw. The valve seat 13 has a third through hole 19 that penetrates from the flow path 20 to the second space 18. The end of the coil spring 24 on the pressure distribution plate 4 side is in contact with the end surface of the valve seat 13 on the suction surface 3 side.

  The large-diameter portion 12a of the piston 12 partitions the space in the cylinder of the cylinder 11 into a first space 17 and a second space 18 in the cylinder axis direction. The piston 12 is slidable in the space inside the cylinder of the cylinder 11 along the cylinder axis. When the air pressure in the first space 17 is equal to the air pressure in the second space 18, the piston 12 is urged by the urging force of the coil spring 24, and the ring packing 25 and the suction surface 3 side of the valve seat 13 are located. A state where the gap between the end surfaces of the two is open is maintained. As will be described in detail later, when the air pressure in the second space 18 decreases, the piston 12 distributes the pressure in the space inside the cylinder of the cylinder 11 due to the pressure difference between the first space 17 and the second space 18. Slide toward the plate 4 side.

  As shown in FIG. 3A, the suction base 2 has a communication groove portion 15 and an outer groove portion 14 which are groove portions recessed on the pressure distribution plate 4 side of the suction surface 3 on the suction surface 3. The communication groove portion 15 and the outer groove portion 14 extend along the suction surface 3 and open toward the suction surface 3 side. The outer groove 14 surrounds the opening of the first through hole 8 in the suction surface 3 and is continuously connected and closed. The communication groove 15 communicates the outer groove 14 and the first through hole 8. The suction base 2 has an object support 16 on the suction surface 3 that is flush with the suction surface 3. That is, the surface of the object support 16 facing the object 7 is the same height as the suction surface 3 and is flush with the suction surface 3 (configures the same plane). The object support 16 is located between the communication groove 15 and the outer groove 14 and supports the object 7 placed on the suction surface 3. In the present embodiment, the outer groove portion 14 has a circular shape.

Here, the atmospheric pressure and Pa, the vacuum pressure of Pv, the pressure in the second space 18 and Pv ', the spring constant of the coil springs 24 and k, the inner diameter of the cylinder of the cylinder 11 and D _1, the throttle portion an inner diameter of 22 is d, the inner diameter of the ring gasket 25 and D _2, the outer diameter of the outer groove 14 and D _3, the distance between the end surface of the suction surface 3 of the ring gasket 25 and the valve seat plate 13 was set to δ In this case, the present embodiment satisfies the following relationships of Equation 1, Equation 2, and Equation 3. The atmospheric pressure Pv ′ in the second space 18 is a pressure reduced by air passing through the throttle portion 22 having the inner diameter d.

In the present embodiment, the outer diameter D ₃ of the outer groove portion 14 is larger than the inner diameter D ₁ of the cylinder of the cylinder 11. By doing in this way, the target object 7 placed on the suction surface 3 can be suctioned more strongly.

(Operation of auto valve 10)
(Operation when the object 7 is on the auto valve 10)
FIG. 4 is a view for explaining the operation of the auto valve 10 under the position where the object 7 is placed, and is a side sectional view of the auto valve 10. In the state shown in FIG. 4, when the valve 6 is opened and air is sucked through the pipe 5 by the vacuum pressure generator, the openings on the suction surface 3 of the first through hole 8, the outer groove portion 14, and the communication groove portion 15 are Since the object 7 is closed, the atmospheric pressure in the first space 17 cannot be maintained, and decreases as the atmospheric pressure in the second space 18 decreases. In this way, in the case of FIG. 4, since the atmospheric pressure in the first space 17 and the atmospheric pressure in the second space 18 are equal, the piston 12 is urged by the urging force of the coil spring 24 and the ring packing 25 and The state where the space between the end face on the suction surface 3 side of the valve seat 13 is opened is maintained. For this reason, the object 7 is sucked and fixed to the suction surface 3 by suction of air through the pipe 5.

  In addition, in the state of FIG. 4, the object 7 is in contact with the object support unit 16 and supported by the object support unit 16. For this reason, even if the object 7 is thin, it can be prevented from being bent and deformed by suction. In addition, according to the present embodiment, the object 7 is adsorbed by the first through hole 8, the outer groove portion 14, and the communication groove portion 15, so that the adsorption is stronger than in the case of adsorbing only by the first through hole 8. Adsorbs stably with force.

  That is, when the object 7 closes the openings in the suction surface 3 of the first through hole 8, the outer groove portion 14, and the communication groove portion 15, the first space 17, the second space 18, and the flow path 20 (third space). ) To form a closed space and suck the air from the flow path 20 through the pipe 5 to suck the object 7 to the suction surface 3.

  By the way, when the object 7 is placed on the suction surface 3, there is a slight gap between the object 7 and the suction surface 3. For this reason, in the case where the throttle portion 22 is not provided, if the valve 6 is opened and air is sucked through the pipe 5, the first space 17 passes through the first through-hole 8 after a predetermined time has elapsed. The piston 12 is pushed downward in the figure due to the air flowing into the valve and gradually moves, and eventually the valve closes (the ring packing 25 causes the gap between the end face 26 and the valve seat 13 to be closed). It will close). Thus, once the valve is closed, there arises a problem that the suction of the object 7 is released. Therefore, by providing the second through hole 21 having the throttle portion 22 between the first space 17 and the second space 18 so that a limited flow rate flows, the object 7 and the suction surface 3 Even if air leaks from a slight gap between the first space 17 and the air flows into the first space 17, the air can be exhausted to the pipe 5, and the adsorption state can be maintained. However, when the object 7 is not placed on the suction surface 3, the hole diameter of the throttle portion 22 has a sufficient atmospheric pressure difference with the first space 17 to cause the piston 12 to move downward. It must be designed to occur between the two spaces 18.

(Operation when there is no object 7 on the auto valve 10)
As shown in FIG. 3B, when the object 7 is not on the auto valve 10 and the valve 6 is opened and air is sucked through the pipe 5 by the vacuum pressure generator, the first through hole is obtained. 8. Openings in the suction surface 3 of the outer groove portion 14 and the communication groove portion 15 are open to the atmosphere without being blocked. For this reason, the atmospheric pressure of the second space 18 decompressed by passing through the throttle portion 22 of the second through hole 21 becomes lower than the atmospheric pressure of the first space 17, and the piston 12 It slides toward the pressure distribution plate 4 against the urging force of the coil spring 24. From the relationship of the above formulas (1), (2), and (3), the piston 12 moves a distance δ, and the ring packing 25 comes into contact with the end surface of the valve seat 13 on the suction surface 3 side. This state is shown in FIG.

  5A and 5B are diagrams for explaining the operation of the auto valve 10 at a position deviated from the position where the object 7 is placed. FIG. 5A is a side sectional view of the auto valve 10, and FIG. It is the top view which looked at the piston 12 of (a) from the top. As shown in FIG. 5A, when the ring packing 25 comes into contact with the end surface of the valve seat 13 on the suction surface 3 side, suction through the pipe 5 by the vacuum pressure generator sucks the end surface 26 of the small diameter portion 12b. Then, the state shown in FIG. 5A is maintained, and no air flows. For this reason, according to the present embodiment, there is no air flow even in the auto valve 10 at a position deviated from the position where the object 7 is placed, there is no air flow leakage, and the vacuum state is kept small. This can be performed with a suction force, and the configuration can be simplified and the cost can be reduced.

  That is, when the openings in the suction surface 3 of the first through hole 8, the outer groove portion 14, and the communication groove portion 15 are opened, air is sucked from the flow path 20 (third space) through the pipe 5. The piston 12 slides due to a pressure difference between the first space 17 and the second space 18, and the small diameter portion 12b (valve element) penetrates the third through against the urging force of the coil spring 24 (urging member). The hole 19 is closed.

(Example with filter)
FIG. 6 is a sectional side view showing the structure of the auto valve according to Embodiment 2 of the present invention. In FIG. 6, the same components as those of the auto valve 10 according to the first embodiment shown in FIGS. 3A and 3B are denoted by the same reference numerals, and detailed description thereof is omitted. The auto valve 100 according to the second embodiment shown in FIG. 6 has a first through hole 108 having a recess 30 instead of the first through hole 8 according to the first embodiment. A filter 31 is accommodated in the recess 30. The filter 31 has air permeability.

  Cutting may be performed on the object 7 sucked and fixed by the vacuum chuck. In this case, the vacuum chuck may be used in an environment where foreign matters such as chips are scattered. According to the present embodiment, by arranging the filter 31 in the first through hole 108, it is possible to prevent foreign matter from entering the cylinder 11 and prevent malfunction and damage.

(Examples with different outer groove shapes)
FIG. 7 is a plan view of the vacuum chuck according to the third embodiment of the present invention as viewed from above. The vacuum chuck 201 according to this embodiment includes a plurality of auto valves 200. The structure of the vacuum chuck 201 is the same as that of the vacuum chuck 1 described with reference to FIGS. The internal structure of the auto valve 200 is the same as that of the auto valve 10 described with reference to FIG. As shown in FIG. 3A, in the auto valve 10 according to the first embodiment, the outer groove portion 14 has a circular shape. However, in this embodiment, the outer groove portion 14 in the first embodiment is replaced with a rectangular outer portion. A groove 214 is provided.

  In this embodiment, the first through hole 208 is provided instead of the first through hole 8 of the first embodiment, and the communication groove portion 215 is provided instead of the communication groove portion 15 of the first embodiment. The object support part 216 is provided instead of the object support part 16 and the through hole 202a is provided instead of the cylindrical hollow part 2a of the first embodiment. The configuration of this embodiment instead of the configuration of the first embodiment is the same as that of the first embodiment except for the points described here.

  The outer groove 214 surrounds the opening of the first through hole 208 and is continuously connected and closed. The communication groove 215 communicates the outer groove 214 and the first through hole 208. The object support part 216 is located between the communication groove part 215 and the outer groove part 214 and supports the object 7 placed on the suction surface 3.

  The shape of the outer groove may be determined according to the shape of the attracted surface of the object 7. For example, when there are a variety of objects 7 to be handled, it is desirable to provide a plurality of autovalves having outer grooves of the same pattern in a circular shape or a rectangular shape in order to give the vacuum chuck versatility. On the other hand, when the shape and size of the object 7 to be handled are limited, the outer groove portion is not limited by size limitation such as the size of the cylinder inner diameter, shape limitation such as circular shape or rectangular shape, and the object 7 It is desirable that the shape of the adsorbed surface is a closed groove shape.

(Example in which the piston has a D-cut)
FIGS. 8A and 8B are views showing the structure of a piston according to Embodiment 4 of the present invention, in which FIG. 8A is a plan view of the piston as viewed from above, and FIG. 8B is a perspective view of the piston. In this embodiment, a piston 312 shown in FIGS. 8A and 8B is provided instead of the piston 12 of the first embodiment. Since other configurations are the same as those of the first embodiment, description of the other configurations is omitted. Moreover, the piston 312 is the same as the piston 12 of Example 1 except the point demonstrated here.

  The piston 312 has a large diameter part 312a disposed on the suction surface 3 side and a small diameter part 312b disposed on the pressure distribution plate 4 side. The piston 312 replaces the second through hole 21 of the first embodiment, and a gap between the inner peripheral surface of the cylinder 11 and the cut surface 312e of the large diameter portion 312a (that is, the inner periphery and the large diameter portion of the cylinder 11). And a gap between the outer periphery of 312a. In this embodiment, a part of the outer periphery of the large diameter portion 312a is scraped off from the end surface 312c of the large diameter portion 312a on the suction surface 3 side to the end surface 312d of the large diameter portion 312a on the pressure distribution plate 4 side (D cut). And the cut surface 312e is exposed.

  The flow path step area of the gap between the inner peripheral surface of the cylinder 11 and the cut surface 312 e is smaller than the flow path step area of the first through hole 8. By providing a constricted portion in the gap between the inner peripheral surface of the cylinder 11 and the cut surface 312e, the flow passage step area of the gap between the inner peripheral surface of the cylinder 11 and the cut surface 312e is set to the first through hole 8. It may be smaller than the channel step area. According to the present embodiment, it is possible to easily form a gap between the inner peripheral surface of the cylinder 11 and the cut surface 312e as the second through hole. According to the present embodiment, since the D-cut is provided instead of the second through hole 21 and the narrowed portion 22 of the first embodiment, the manufacturing cost can be kept low. Further, in the case of a configuration having a D-cut like the piston 312, the piston 312 may rattle or vibrate in the cylinder 11, making it difficult to accurately control the air flow rate. Since the structure corresponding to the ring seal 23 of Example 1 is unnecessary, the cost can be reduced accordingly.

(Example in which the groove on the outer peripheral surface of the piston is the second through hole)
9A and 9B are views showing the structure of a piston according to Embodiment 5 of the present invention, in which FIG. 9A is a plan view of the piston as viewed from above, and FIG. 9B is a perspective view of the piston. In this embodiment, instead of the piston 12 of the first embodiment, a piston 412 shown in FIGS. 9A and 9B is provided. Since other configurations are the same as those of the first embodiment, description of the other configurations is omitted. Moreover, the piston 412 is the same as the piston 12 of Example 1 except the point demonstrated here.

  The piston 412 has a large diameter part 412a disposed on the suction surface 3 side and a small diameter part 412b disposed on the pressure distribution plate 4 side. Instead of the second through-hole 21 of the first embodiment, the piston 412 has a gap between the inner peripheral surface of the cylinder 11 and the groove portion 412e provided on the outer peripheral surface of the large diameter portion 412a (that is, the inner periphery of the cylinder 11). And a gap between the outer periphery of the large diameter portion 412a). In the present embodiment, a part of the outer periphery of the large diameter portion 412a is scraped off from the end surface 412c of the large diameter portion 412a on the suction surface 3 side to the end surface 412d of the large diameter portion 412a on the pressure distribution plate 4 side, thereby forming the groove portion 412e. Is forming. The cross-sectional shape of the groove 412e may be U-shaped or V-shaped. When the cross-sectional shape of the groove 412e is U-shaped, for example, it can be processed by a mill using a ball end mill.

  The flow path step area of the gap between the inner peripheral surface of the cylinder 11 and the groove portion 412 e is smaller than the flow path step area of the first through hole 8. By providing a constricted portion in the gap between the inner peripheral surface of the cylinder 11 and the groove portion 412e, the flow path area of the gap between the inner peripheral surface of the cylinder 11 and the groove portion 412e can be reduced. It may be smaller than the road step area. According to the present embodiment, it is possible to easily form a gap between the inner peripheral surface of the cylinder 11 and the groove portion 412e as the second through hole. According to the present embodiment, since the groove portion 412e is provided in place of the second through hole 21 and the throttle portion 22 of the first embodiment, the manufacturing cost can be kept low. Further, in the case of the structure having the groove 412e like the piston 412, there is a possibility that the piston 412 rattles or vibrates in the cylinder 11 and it becomes difficult to control the air flow rate accurately. Since the structure corresponding to the ring seal 23 of Example 1 is unnecessary, the cost can be reduced accordingly.

(Example in which the gap between the piston and the cylinder is the second through hole)
10A and 10B are diagrams showing an auto valve according to Embodiment 6 of the present invention, in which FIG. 10A is a plan view of the auto valve as viewed from the suction surface 3 side, and FIG. FIG. The auto valve 510 of this embodiment has a piston 512 shown in FIG. 10B instead of the piston 12 of the first embodiment. Since other configurations are the same as those of the first embodiment, description of the other configurations is omitted. Moreover, the piston 512 is the same as the piston 12 of Example 1 except the point demonstrated here.

  The piston 512 has a large diameter part 512a arranged on the suction surface 3 side and a small diameter part 512b arranged on the pressure distribution plate 4 side. In the present embodiment, the diameter of the large diameter portion 512a is smaller than the diameter of the large diameter portion 12a of the first embodiment. In the present embodiment, there is a gap between the inner peripheral surface of the cylinder 11 and the outer peripheral surface of the large diameter portion 512a as the second through hole 521 instead of the second through hole 21 of the first embodiment. The diameter of the large diameter portion 512a and the diameter of the end surface 512c on the suction surface 3 side are equal to the diameter of the large diameter portion 512a and the end surface 512d on the pressure distribution plate 4 side. The diameter of the end surface 512c may be different from the diameter of the end surface 512d.

  A ring packing 25 is provided on the end surface 526 of the small diameter portion 512b of the piston 512 on the pressure distribution plate 4 side. When the piston 512 slides and the ring packing 525 comes into contact with the end surface of the valve seat 13 on the suction surface 3 side, the end surface 526 and the valve seat 13 are sucked by the ring packing 25 provided on the small diameter portion 512b as a valve body. The space between the end surface on the surface 3 side is closed, and the airtightness between the second space 18 and the third through hole 19 is maintained.

In this embodiment, the inner diameter of the cylinder of the cylinder 11 and D _1, the diameter of the large-diameter portion 512a and D _4, when the flow path stage area of the first through-hole 8 has a S, this embodiment, the following The relationship of Equation 4 is satisfied. That is, the flow path step area of the gap between the inner peripheral surface of the cylinder 11 and the outer peripheral surface of the large diameter portion 512 a is smaller than the flow path step area S of the first through hole 8.

  In addition, the flow of the gap between the inner peripheral surface of the cylinder 11 and the outer peripheral surface of the large-diameter portion 512a is provided by providing a throttle portion in the gap between the inner peripheral surface of the cylinder 11 and the outer peripheral surface of the large-diameter portion 512a. The road step area may be smaller than the flow path step area of the first through-hole 8. According to the present embodiment, it is possible to easily form a gap between the inner peripheral surface of the cylinder 11 and the outer peripheral surface of the large diameter portion 512a as the second through hole. According to the present embodiment, instead of the second through hole 21 and the narrowed portion 22 of the first embodiment, the diameter of the large diameter portion 512a is reduced, so that the manufacturing cost can be kept low. In addition, when the diameter of the large-diameter portion 512a is small like the piston 512, the piston 512 may rattle or vibrate in the cylinder 11 and it may be difficult to accurately control the air flow rate. On the other hand, the process of opening the second through-hole 21 and the process of attaching the groove in FIG. 3 are unnecessary, and further, the configuration corresponding to the ring seal 23 of the first embodiment is unnecessary, and the cost is reduced accordingly. be able to.

  For example, when the weight of the object placed on the vacuum chuck 1 is relatively light, the suction base 2 can be changed to a plate-like member having the suction surface 3 and the first through hole 8. It is. By changing in this way, the end of the cylinder 11 opposite to the third through hole is connected to the plate member without a gap, and the flange portion of the cylinder 11 becomes unnecessary. It becomes a simple structure and can reduce manufacturing cost.

  Further, the suction base 2, the cylinder 11, and the piston 12 of the vacuum chuck 1 may be made of a transparent material such as glass or acrylic, and the present invention may be applied to a stage of an optical instrument such as a microscope or an image measuring machine. Is possible. In this case, since the vacuum chuck 1 is relatively light and transparent, there is an effect that the backlight illumination of the optical device is not hindered.

  In addition, this invention is not limited to an above-described Example, Various modifications are included. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Further, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

  DESCRIPTION OF SYMBOLS 1 ... Vacuum chuck, 2 ... Adsorption base, 3 ... Adsorption surface, 4 ... Pressure distribution plate, 5 ... Piping, 6 ... Valve, 7 ... Object, 10 ... Auto valve.

Claims (10)

An adsorption base having an adsorption surface for adsorbing an object;
A cylinder provided inside the suction base;
A piston that divides the cylindrical space of the cylinder into a first space and a second space in a cylindrical axis direction, and that can slide along the cylindrical axis in the cylindrical space;
A third space communicating with the vacuum pressure generator;
A first through hole penetrating the adsorption base from an opening in the adsorption surface to the first space;
A second through-hole penetrating between the first space and the second space and capable of maintaining a pressure difference between the first space and the second space;
A third through hole penetrating between the second space and the third space;
A valve body that is provided in the piston and closes the third through hole by sliding the piston due to a pressure difference between the first space and the second space;
A biasing member that biases the valve body in a direction to open the third through hole;
A groove portion having an opening communicating with the first through hole and extending along the suction surface;
An auto valve for a vacuum chuck characterized by comprising An auto valve for a vacuum chuck according to claim 1,
When an object closes the opening in the suction surface of the first through hole and the groove, a closed space is formed by the first space, the second space, and the third space, and the vacuum The object is adsorbed on the adsorption surface by sucking air from the third space by the pressure generator,
This is an auto valve for vacuum chucks. An auto valve for a vacuum chuck according to claim 1 or 2,
When the opening in the adsorption surface of the first through hole and the groove is opened, the first space and the second space are formed by sucking air from the third space by the vacuum pressure generator. The piston slides due to a pressure difference with the space, and the valve body closes the third through hole against a biasing force by the biasing member.
This is an auto valve for vacuum chucks. An auto valve for a vacuum chuck according to any one of claims 1 to 3,
An inner diameter of the first through hole is smaller than an inner diameter of the cylinder;
This is an auto valve for vacuum chucks. An auto valve for a vacuum chuck according to any one of claims 1 to 4,
The groove is
A closed outer groove portion continuously surrounding and surrounding the opening of the first through hole in the suction surface;
A communication groove portion communicating the outer groove portion and the first through hole;
Have
The suction surface has an object support part for supporting an object between the first through hole and the outer groove part.
This is an auto valve for vacuum chucks. An auto valve for a vacuum chuck according to claim 5,
The outer groove is a circular shape having a diameter larger than the inner diameter of the cylinder.
This is an auto valve for vacuum chucks. An auto valve for a vacuum chuck according to any one of claims 1 to 6,
The diameter of at least a part of the second through hole is smaller than the diameter of the first through hole,
This is an auto valve for vacuum chucks. An auto valve for a vacuum chuck according to any one of claims 1 to 7,
The second through hole is a gap between the outer periphery of the piston and the inner periphery of the cylinder.
This is an auto valve for vacuum chucks. An auto valve for a vacuum chuck according to claim 8,
The second through hole is a groove provided on the outer periphery of the piston.
This is an auto valve for vacuum chucks. The suction base includes a plurality of the vacuum chuck auto valves according to any one of claims 1 to 9,
A vacuum chuck characterized by that.

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