JP3408780B2 - Vacuum gripper and IC test handler - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum gripping device having a suction pad used in an IC test handler or the like, and in particular, it is possible to make the suction pad material rigid or metallizable and to make the suction pad flexible. The present invention relates to a vacuum gripping device capable of ensuring swinging characteristics and ensuring a light elastic lifting stroke.

[0002]

2. Description of the Related Art A manufactured IC (semiconductor integrated circuit device)
Are subjected to electrical tests to determine their suitability for operation. For the electrical test of such an IC, an IC tester is used for contacting the IC with an IC socket having a large number of lead pins, applying a power source and a predetermined pattern signal from the outside, and measuring a signal generated from the IC. . A large number of manufactured ICs of the same kind are usually carried one by one from the take-in position to the test position by the IC test handler (IC handling and conveying device) as a manipulator, then lowered and pressed into contact with the IC socket. After the electrical test of (1), the tested IC is separated from the IC socket and carried out to the take-out position.

FIG. 6 shows I disclosed in Japanese Patent No. 2816114.
It is sectional drawing which shows the head part in C test handler. An IC socket 2 having a large number of lead pins 2a is fixed at a test position on a test stand 1 of the IC test handler. The IC socket 2 is connected to an IC tester body (not shown). And I as a head component
The IC test handler 5 that sucks and grips C3 has a lateral feed mechanism (Y-axis direction drive mechanism) composed of a ball screw and the like, and a lifting mechanism (Z-axis direction drive mechanism) composed of a pinion and a rack and the like. , These are L-shaped arm 1
2 is movable in the Y-axis direction and the Z-axis direction in the figure. IC3 is provided on the lower surface of the horizontal end piece 12a of the L-shaped arm 12.
A cup-shaped IC retainer 14 for pressing the large number of lead pins 3a to the lead pins 2a of the IC socket 2 is fixed by screws or the like. A vacuum gripping device 20 made of stainless steel is fixed to the inside of the IC retainer 14 by screwing a bolt portion 22a downward. Bolt hole 14a of IC retainer 14
Is connected to a vacuum source (not shown) via an intake hole 17 and a flexible intake pipe 18 of the horizontal end piece 12a of the L-shaped arm 12.

For example, I placed at an intake position (not shown)
When C3 is conveyed to the test position and further conveyed from the test position to the take-out position, the arm 12 is brought right above the IC3 at the take-in position and the arm 12 is driven in the Z direction to move the vacuum gripping device 20. When the air inside the cavity of the stainless steel suction pad 26 is sucked through the flexible intake pipe 18 while being lowered, the suction surface (opening edge) of the suction pad 26 almost sucks the IC3 when the suction surface (opening edge) almost contacts the upper surface of the IC3. The cavity inside the suction pad 26 is completely blocked by the IC3, which causes a momentary pressure reduction of the cavity pressure, and as will be described later, the suction pad 26 is a bearing member elastically holding the IC3. The lead pin 3a of the IC 3 is received by the lower end of the IC positioning receiver 14 because the lead pin 3a of the IC 3 is slightly displaced upward. After that, the arm 12 is driven in the Y-axis direction and lowered in the Z-axis direction near the test position, and the gripped IC 3 is brought into pressure contact with the IC socket 2. After a required electric test is performed by the IC tester while holding the IC 3 while holding it by the IC retainer 14, the IC 3 that has been tested is moved upward in the Y-axis direction while being pulled up, and at a take-out position (not shown). When the suction operation is stopped by lowering the suction operation, the internal pressure of the suction pad 26 is restored to the atmospheric pressure, so that the suction pad 26 releases the IC3 and the IC3 is placed on the take-out position.

The vacuum gripping device 20 does not have a bellows-like suction pad made of rubber, but has a suction pad 26 made of stainless steel as shown in FIG. That is,
This vacuum gripping device 20 includes a bearing member 22 having a bolt portion 22a having an axial intake passage 22c, and a movable intake nozzle shaft 24 axially supported by a first O-ring 23. , The second O-ring 2 fitted to this
5 is provided on the inner peripheral surface of the suction pad 26 made of stainless steel, and the suction surface 26b is set to protrude from the nozzle opening 24d by a gap length L of about the suction displacement amount. The suction pad 26 is capable of swinging motion with a certain degree of elastic restoring force due to the swinging motion of the intake nozzle shaft 24 and the elastic deformation of the second O-ring 25 that is synergistic with this. For this reason, it is possible to exhibit a certain degree of adherability to the attracted surface from various directions. Further, since the suction displacement amount after suction is the sum of the axial displacement amounts of the intake nozzle shaft 24 and the second O-ring 25, it is possible to raise the gap length L of the suction target. Further, the suction pad 26 itself can be made of metal parts.

[0006]

However, the above vacuum gripping device 20 has the following problems.

As an airtight member, the swing movement of the intake nozzle shaft 24 with respect to the bearing member 22 due to the elastic deformation of the first O-ring 23 and the neck of the suction pad 26 with respect to the intake nozzle shaft 24 due to the elastic deformation of the second O-ring 25. Although it is possible to obtain a swinging swing motion having an elastic restoring force of the suction pad 26 with respect to the bearing member 22 to some extent by a synergistic action with the swinging motion, the O ring positioning accommodating portion 22e of the bearing member 22 does not move to the first O ring 23. Positioning and restraining the outer peripheral surface side, and the O-ring positioning accommodating portion 26 of the suction pad 26
Since “a” also positions and restrains the outer peripheral surface side of the second O-ring 25, the swinging playability of the suction pad 26 is obtained only by the crushing deformation of the O-ring. Since the crushing deformation of the O-ring within the proportional limit is small, the swinging swing angle is insufficient, and the suction reliability for ICs in a tilted posture is poor. When a soft O-ring having a large elastic coefficient is used, a flexible swinging characteristic can be obtained, but non-uniformity occurs in the O-ring positioning accommodating portions 22e and 26a in the restraint of the O-ring in the circumferential direction. An initial swinging habit is likely to occur on the suction pad 26, the appearance is not good, and the swinging angle in the opposite direction is comparable.

First and second movable intake nozzle shafts 24
The O-ring positioning areas 24a and 24c are substantially V-shaped circumferential groove areas consisting of the diameter-reduced surface C and the tapered surfaces A and B on both sides, and one taper surface B is a gentle taper surface. At one time, one taper surface B bites into the inner peripheral surface of the first O-ring 23 and the inner peripheral surface of the second O-ring 25 bites into the other taper surface B, so that the suction pad 26 has a gap length L only. Although the stroke is displaced, the O-ring is crushed and deformed by the above bite,
It is not possible to obtain a sufficient stroke length.

In view of the above problems, an object of the present invention is to make the suction pad material rigid or metallizable, and to secure a flexible swinging characteristic of the suction pad and a light elastic lifting stroke. It is to provide a vacuum gripping device that can be used.

[0010]

In order to solve the above-mentioned problems, the first means taken by the present invention is a support member having an intake passage communicating with the intake opening at the lower end and a mounting portion, and the intake opening. And a suction pad having an opening facing the intake port with a gap directly below it, and a first positioning orbiting groove formed on the support member and having a first curvature and having a substantially curved cross section. And a second positioning circumferential groove having a second curvature and having a second curvature formed on the suction pad facing the first positioning circumferential groove at a distance from each other. And an O-ring made of an elastic material having a substantially circular cross section having a curvature larger than the first and second curvatures, and the suction pad is an axial downward force against the bearing member when the non-suction is performed, and an initial elastic force is set as a preload. And a compression coil spring for applying.

When the suction passage is connected to a vacuum source and a part of the suction surface of the suction pad hits the suction target surface, the suction pad passes through an O-ring fitted into the second positioning orbiting groove having a substantially concave cross section. Since the second curvature is suspended and supported by the support member and the second curvature is smaller than the curvature of the O-ring, the concave curved surface of the second positioning circuit groove makes rolling contact with the convex curved surface of the O-ring, and the entire suction pad is O-shaped. Since the O-ring is tilted about the ring, a flexible swinging motion is generated without causing excessive crushing deformation of the O-ring, and the entire suction surface is softly and spontaneously attached to the suction target surface. As a result, the cavity inside the suction pad is completely blocked by the suction target surface, the internal pressure is reduced, and the suction pad is pulled up (raised) to the support member side.
Displace. In this pulling up process, the swingback by the initial elastic force of the compression coil spring also acts, and the concave curved surface of the second positioning circuit groove returns and rolls in the opposite direction to the convex curved surface of the O-ring. Returns to a substantially vertical position. At the same time, with the upward displacement of the suction pad, the outer peripheral contact surface of the O-ring does not slide with respect to the concave curved surface of the second positioning circular groove, but is relatively closely displaced in the forward direction by about half of the upward movement amount. At the same time, the inner contact surface of the O-ring does not slide on the concave curved surface of the first positioning circumferential groove and relatively moves in close contact with the concave surface of the first positioning circumferential groove in the forward direction by about half of the amount of rise. Only rises and displaces.

The term "close contact shift of the O-ring" means that the O-ring is sandwiched by the biconcave curved surfaces and is in surface contact with the biconcave curved surface due to the couple force applied to the inner and outer peripheral contact of the O-ring cross section. Means the elastic deformation of the O-ring such that the contact point of the O-ring has an angle (rolling angle) with respect to the neutral point (center) of the cross-section of the O-ring. Is tightly constrained by the concave curved surface, it is not the free contour of the O-ring itself, but the deviation locus following the concave curved surface (first
And a second curvature curve). In other words, it can be considered that a moment is momentarily acting on the contact surface of the second positioning groove with the contact surface of the first positioning circumferential groove as the instantaneous center. This close contact deviation ensures the airtightness during adsorption. The positioning groove is O
In addition to the function of positioning the ring, it is important to secure the contact shift of the O-ring, but if it is only for ensuring the contact shift, the first and second curvatures are zero even if it is not a curved surface. It can be flat. The "concave curved surface" used in the claims of the present invention also includes a flat surface.

Looking at the contact slippage process of the O-ring sandwiched between the concave curved surfaces in a state in which it does not shift (initial free state) when it is not adsorbed
Since the ring is only sandwiched between both concave curved surfaces, the sandwiched cross section can be regarded as a substantially elliptical shape that is pressed into contact with the concave curved surface at the initial contact generatrix width, but as the suction pad is displaced upward, It can be considered that the initial contact point shifts along the concave curved surface by adding a new contact point while separating, and includes shear strain deformation in which a pair of anti-parallel shearing forces are applied to the contact generatrix widths of the inner and outer peripheral surfaces. However, if the groove bottom of the positioning circumferential groove is not a concave curved surface but a flat surface, in principle, the contact bus width is not widened. However, when the stroke is lengthened at the suction force limit or the highest point due to the physical stopper, the shear strain due to the O-ring shift easily exceeds the proportional limit, and Hooke's law is no longer valid there. The range in which Hooke's law holds is when a relatively small distortion occurs. For this reason, when the rolling angle is, for example, several degrees or more, the O-ring undergoes elastic deformation around the shear stress / shear strain characteristic in an exponential non-linear region. It becomes extremely difficult, and the upward stroke of the suction pad cannot be obtained with a light elasticity, and the O-ring itself acts as an elasticity stopper.

However, the present invention is provided with a compression coil spring for applying an initial elastic force as a pre-load to the support member in the suction pad in the axial direction downward when the suction is not performed. Since the contact slippage deformation in the opposite direction to the contact slippage deformation in the direction is set as an offset in advance during non-adsorption, the initial reverse deformation of the O-ring is eliminated in the first half of the rise of the adsorption pad during adsorption. After returning to the neutral (zero point) deformation where the neutral contact busbar width is almost equal to the initial contact busbar width of, the shear strain deformation (forward deformation) due to the contact slippage in the forward direction of the O-ring in the latter half of the rising of the suction pad is first. Occurs. In the process of eliminating the initial reverse deformation, only the restoring force increment within the proportional limit is increased from the initial elastic force of the compression coil spring, and in the process of forward deformation, the compression coil spring and the O-ring are in a parallel relationship, so that within the proportional limit of the compression coil spring. The sum of the restoring force and the elastic restoring force of the O-ring counterbalances the suction force. Therefore, in the forward deformation process, O
Since the ring only needs to compete with the component force of the suction force, even if the elastic force of the O-ring is limited to within the proportional limit, the suction force that provides the degree of adhesion required for workpiece suction is antagonized and a light elastic stroke is achieved. In addition to being able to ensure the above, it is possible to lengthen the lifting stroke of the suction pad by the amount of the offset return return displacement amount of the initial reverse deformation of the O-ring set as an offset.

The compression coil spring sets the initial reverse deformation of the O-ring when it is not attracted, but in order to make the ascending / descending stroke due to the deformation of the O-ring displaced around and the expansion / contraction amount of the compression coil spring match. It is desirable to make the elastic modulus along the vertical direction around the deviation equal to the longitudinal elastic modulus of the compression coil spring. A movable spring retainer for adjusting the spring pressure may be provided. Here, if the initial elastic force of the compression coil spring is set to a value that is the proportional limit of the initial reverse deformation in the direction opposite to the forward direction in which the O-ring closely shifts with the upward displacement of the suction pad during adsorption, You can get a long stroke that doubles. When the initial reverse deformation of the O-ring is set as an offset, the initial elastic restoring force of the compression coil spring can be reduced to some extent by the weight of the suction pad, but the suction pad itself can be used to suck a relatively heavy suction target. Since it is necessary to reduce the weight, it is desirable to set the offset exclusively to the proportional limit of the reverse deformation of the O-ring by the compression coil spring. As a means for biasing the initial stress of the O-ring to the stress on the reverse deformation side, an elastic means other than the compression coil spring can be used, but the compression coil spring is suitable for setting the initial elastic force value.

In the vacuum gripping device having such a structure, since the suction pad can be made rigid or metallized, the vacuum suction function can be exhibited at high temperature and low temperature, and furthermore, the support member can be supported via the compression coil spring. The O-ring itself does not have to be a conductive material, because it is electrically conductively connected to the suction pad and measures against static electricity are taken. Therefore, the degree of freedom in selecting an O-ring made of a durable material is increased. A hollow tubular O-ring may be used.

As a specific example of the vacuum gripping device according to the first means, the support member has a diameter-expanding base portion and a lower-end diameter reducing portion integrally projecting downwardly with the intake port and having an intake port. Has a pad portion having an opening and an upper mouth cylinder portion integrally protruding with the pad portion and surrounding the reduced diameter lower end portion, and the first positioning circumferential groove is an outer peripheral groove formed on the outer peripheral surface of the reduced diameter lower end portion. The second positioning circumferential groove is an inner circumferential groove formed on the inner circumferential surface of the upper mouth cylinder, and the compression coil spring is loaded between the diameter-expanding base and the upper portion of the upper mouth cylinder. Configuration can be adopted. Since the suction pad is located outside the support member, a relatively large suction area can be obtained. As another specific example, the support member has a reduced-diameter inner cylinder portion having an intake port and a lower mouth outer cylinder portion surrounding and surrounding the lower mouth protrusion portion, and the suction pad is surrounded by the lower mouth outer cylinder portion. The first positioning circumferential groove is an inner circumferential groove formed on the inner circumferential surface of the lower mouth outer cylinder portion, the second positioning circumferential groove is an outer circumferential groove formed on the outer circumferential surface of the suction pad, and the coil spring is It is possible to employ a configuration in which the reduced diameter inner cylindrical portion is mounted between the suction pad and the upper portion of the suction pad.
Since the suction pad is located inside the bearing member, a relatively small suction area can be obtained.

As described above, when the O-ring sandwiched by the concave curved surface and the compression coil spring for imparting the initial reverse deformation to the O-ring are used, it is possible to secure the flexibility of the suction pad and the secure stroke. However, in order to secure the flexibility of swinging motion and long stroke, the O
It is advisable to connect a plurality of rings in multiple stages. That is, as the second means of the present invention, a supporting member having an intake passage communicating with the intake port at the lower end and a mounting portion, and an intake hole facing the intake port with a gap just below the intake port are provided. A suction-movable intake nozzle shaft, a swing-movable suction pad having an opening directly below the intake hole and facing the intake hole with a gap, and a first curvature formed on the support member. Having a substantially concave curved cross section, and a second substantially curved curved cross section having a second curvature formed on the intake nozzle shaft body so as to be spaced apart and opposed to the first positioning circular groove. A first O-ring made of an elastic material having a substantially circular cross section and having a curvature larger than the first and second curvatures, the first O-ring being sandwiched so as to be closely contacted with the positioning circumferential groove, and the intake nozzle shaft body. And a third positioning orbiting groove having a third curvature and having a substantially curved cross section. It is sandwiched between the third positioning groove and the fourth positioning groove formed in the suction pad facing the positioning groove and having a fourth curvature and having a substantially curved cross section. A second O-ring made of an elastic material having a substantially circular cross section having a curvature larger than the fourth curvature, and the suction pad applies an initial elastic force as a preload to the support member in the axial downward direction when not adsorbed. And a compression coil spring for.

The intake nozzle shaft is suspended and supported by the support member via the first O-ring, and the suction pad is provided in the second position.
Since it is suspended and supported by the intake nozzle shaft through the O-ring, the swinging property becomes more flexible due to the synergistic effect of the two-stage O-rings, and the first O-ring shift deformation and the second O-ring Since the stroke of the suction pad is twice the sum of the displacement of the O-ring that deviates, the stroke of light elasticity is longer than in the case of a single O-ring.

The initial elastic force of the compression coil spring is the proportional limit of the initial reverse deformation in the opposite direction to the forward direction in which the first and second O-rings are closely displaced around each other due to the upward displacement of the suction pad during adsorption. When set to a value, the light elastic stroke can be doubled compared to when using a single O-ring.

The above vacuum gripping device can be used for various manipulators, but is suitable for use in an IC test handler.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the accompanying drawings.

[0023]

[Embodiment 1] FIG. 1 is a vertical sectional side view showing a main part of a vacuum gripping apparatus according to Embodiment 1 of the present invention. The state shown in FIG. 1 is a state where the suction pad 60 is at a half stroke s / 2 position. The vacuum gripping device 40 of the present example has a mounting portion (not shown) similar to the bolt portion 22a as shown in FIG. 6 at the upper end and a stainless steel bearing having an intake passage 52 communicating with the intake port 52a at the lower end. The member 50, a suction pad 60 made of stainless steel which is free to swing and has an opening 62a directly below the air intake port 52a and facing the air intake port 52a with a gap g, and a first member having a concave cross section formed on the support member 50. Silicon rubber or the like sandwiched between the first positioning circumferential groove 56a and the second positioning circumferential groove 66a formed in the suction pad 60 so as to be spaced apart and opposed to the circumferential groove 56a so as to be closely displaced. And an O-ring 70 made of an elastic material, and a compression coil spring 8 for applying an initial elastic force as a pre-load to the support member 50 by the suction pad 60 when not attracted.
It has 0 and.

The support member 50 has an enlarged diameter base portion 54 and a reduced diameter lower end portion 56 integrally projecting downwardly in the axial direction and having an intake port 52a, and an outer peripheral surface of the reduced diameter lower end portion 56. A first positioning circumferential groove 56a is formed. The suction pad 60 has a pad portion 62 having an opening 62 a and an upper mouth cylinder portion 66 that integrally projects with the pad portion 62 and surrounds the reduced diameter lower end portion 56. The second positioning circumferential groove 66a is formed. Compression coil spring 70
Is mounted between the outer peripheral step portion 54b of the enlarged diameter base portion 54 and the upper spring receiver 66b of the upper mouth cylinder portion 66.

In this example, the first curvature of the first positioning circumferential groove 56a and the second curvature of the second positioning circumferential groove 66a are made equal to each other, but as shown in FIG. The second curvature is smaller than the curvature of the O-ring 70, and the contact point of the O-ring 70 with the curved surface can shift around the center O of the cross section.

The end surface of the diameter-reduced lower end portion 56 serves as a stopper surface that regulates the upper limit point of the lifting stroke, and the gap g when not adsorbing is the stroke s. The suction passage 52 is connected to a vacuum source (not shown), and the suction pad 6 is attached to the suction target surface 90.
When a part of the suction surface of 0 hits, the suction pad 60 fits in the second positioning orbiting groove 66a having a concave cross section, and the O-ring 70.
It is hung and supported by the support member 50 via the
Is smaller than the curvature of the O-ring 70, the concave curved surface of the second positioning circumferential groove 66a makes rolling contact with the convex curved surface of the O-ring 70 as a substantially immovable body, and the entire suction pad is centered on the O-ring 70. Then tilt. Therefore, without causing excessive crushing deformation of the O-ring 70, a flexible swinging movement occurs and the entire suction surface is softly and spontaneously attached to the suction target surface 90. As a result, the suction pad 6
The cavity inside 0 is completely blocked by the suction target surface, the internal pressure is reduced, and the suction pad 60 is supported by the support member 5.
It is pulled up (raised) and displaced to the 0 side. In this pulling up process, swingback by the initial elastic force of the compression coil spring 80 also acts and the concave curved surface of the second positioning circumferential groove 66a rolls back on the convex curved surface of the O-ring 70 in the direction opposite to the above-described swing. The posture of the suction pad 60 returns to the substantially vertical posture. At the same time, with the upward displacement of the suction pad,
The outer peripheral contact surface of the O-ring 70 has a second positioning circular groove 66.
Without slipping on the concave curved surface of a, the amount of relative rise is closely shifted in the forward direction of arrow a by approximately s / 2, and O
The inner circumferential contact surface of the ring 70 has a first positioning circumferential groove 56a.
Since it does not slide with respect to the concave curved surface, it relatively closely moves about s / 2 of the amount of rise in the forward direction of the arrow a, so that the suction pad 60 moves upward by the stroke s.

In this example, the suction pad 6 is used when not adsorbed.
A compression coil spring 80 for applying an initial elastic force f ₀ as a preload to the bearing member 50 downward in the axial direction is provided with ₀ , and the O-ring 70 is deformed around the contact shift in the forward direction a during adsorption (FIG. 2 (c)), the O-ring 70 is set as an offset for the contact slip displacement deformation in the opposite direction b (FIG. 2 (a)).

Here, in the non-adsorbed state, when the O-ring 70 as shown in FIG. 2B has a free contour and is sandwiched between the biconcave mirror surfaces for initialization, the O-ring 70 is simply O-adsorbed in the non-adsorbed state.
Since the ring 70 is only sandwiched between the both concave curved surfaces, the sandwiched cross section can be regarded as a substantially elliptical shape that is pressed into contact with the concave curved surface at the initial contact generatrix width w _0.
It can be considered that as 0 is displaced upward, a new contact point is added while the initial contact point is separated, and it shifts along the concave curved surface. As shown in c), the contact generatrix width w _{1 is obtained} , and this contact deviation process in the forward direction a includes shear strain deformation in which a pair of antiparallel shear forces T are applied to the contact generatrix width of the inner and outer peripheral contact surfaces. It can be considered that tensile stress acts outside the shearing force on the outer peripheral side surface, and compressive stress occurs outside the shearing force on the inner peripheral side surface. Note that FIG. 2 does not show swelling in the vicinity of the inner and outer contact surfaces due to tension and compression. This contact deviation is caused by the center O of the O-ring 70.
In other words, a moment is momentarily applied to the contact surface of the second positioning groove 66a with the contact surface of the first positioning groove 56a as the instantaneous center. Can be seen as When the stroke is lengthened at the suction force limit or the highest point due to the physical stopper, as shown in FIG. 3, the shear strain δ due to the shift of the O-ring 70 easily exceeds the proportional limit σ _max of the shear stress σ. , Where Hooke's law no longer holds. The range in which Hooke's law holds is when a relatively small distortion occurs. Therefore, when the rolling angle becomes, for example, several degrees or more, as shown in A of FIG.
Since 0 is the elastic deformation of the shear stress / shear strain characteristic in the non-linear region of exponential function, the shearing becomes extremely difficult due to the occurrence of excessive shear stress, and the lifting stroke of the suction pad 60 is lightly elastic. It is not possible to obtain a large size, and the O-ring 70 itself acts as an elastic stopper.

However, in this example, the compression coil spring 80
As a result, when the O-ring 70 is attracted, the O-ring 70 is offset and set so as to be deformed in close contact deviation in the forward direction a (FIG. 2 (c)) and deformed in close contact deviation in the reverse direction b (FIG. 2 (a)). And the initial contact bus width is w ₁ due to the symmetry. This offset setting is in the reverse direction b as shown in FIG.
It is preferable to set the proportional limit σ _{max in} . At the time of adsorption, first, the O-ring 70 in the first half of the rise of the adsorption pad 60
After returning to the neutral (zero point) deformation in which the initial reverse deformation of No. 1 is eliminated and the neutral contact bus width w ₀ shown in FIG. 2B is reached, the adhesion of the O-ring 70 in the forward direction a in the latter half of the rise of the suction pad is first performed. Shear strain deformation (forward deformation) occurs due to slippage. In the process of eliminating the initial reverse deformation, only the restoring force increment within the proportional limit σ _max increases from the initial elastic force of the compression coil spring 80, and in the process of forward deformation, the compression coil spring 80 and the O-ring 70
And are in parallel relationship, the sum of the restoring force of the compression coil spring 80 within the proportional limit and the elastic restoring force of the O-ring 70 is balanced against the suction force. Therefore, in the forward deformation process, the O-ring 70 only has to compete with the component force of the suction force, so that the elastic force of the O-ring 70 is reduced to the proportional limit σ as shown in FIG. 3B.
Even when it is limited to _max , a light elastic stroke can be ensured by competing with the suction force that obtains the degree of adhesion required for IC suction, and the offset reverse return displacement amount s / The amount by which the suction pad 60 is lifted can be lengthened by two.

[0030]

[Embodiment 2] FIG. 3 is a vertical sectional side view showing a main part of a vacuum gripping apparatus according to Embodiment 2 of the present invention. The state shown in FIG. 3 is the state at the half stroke position of the suction pad 160, and the same portions as those shown in FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted.

In the vacuum gripping device 140 of this example, the support member 150 has a reduced diameter inner cylinder portion 154 having an intake port 52a and a lower mouth outer cylinder portion 156 that surrounds this and projects downward. The suction pad 160 has a substantially tubular shape and is surrounded by the lower mouth outer tubular portion 156. A first positioning circumferential groove 156a is formed on the inner peripheral surface of the lower mouth outer tubular portion 156, and a second positioning circumferential groove 166a is formed on the outer peripheral surface of the suction pad 160. The compression coil spring 180 is mounted between the outer peripheral surface of the diameter-reduced inner cylinder portion and the upper spring receiver 162 of the suction pad 160.

Also in this example, by the same operation as that of the first embodiment, it is possible to realize a flexible swinging free play and a light elastic stroke, but in the first embodiment, the suction pad 60 is provided.
Is located outside the support member 50, a relatively large suction area can be obtained, whereas in this example, the suction pad 160 is located inside the support member 150, so a relatively small suction area can be obtained. You can

[0033]

[Embodiment 3] FIG. 5 is a vertical sectional side view showing a main part of a vacuum gripping apparatus according to Embodiment 3 of the present invention. The state shown in FIG. 1 is the state of the suction pad 260 at the half stroke position.

The vacuum gripping device 240 of this embodiment includes a support member 250 having an intake passage 242 communicating with the intake port 242a at the lower end and a mounting portion (not shown), and a gap G ₁ just below the intake port 242a. Intake hole (shaft through hole) 25
2. An intake nozzle shaft body 255 equipped with a swingable and swingable body,
Beneath this potential swing idler to the gap G ₂ with an opening 266a facing me than cylindrical adsorption air inlets 252 Pad 2
And 60. The support member 250 has an intake port 242a.
251 having a base and a lower mouth tube portion 253 protruding downward
And have. The vacuum gripping device 240 includes a first positioning circumferential groove 253a having a concave cross section formed on the inner circumferential surface of the lower mouth cylinder 253 and an outer periphery of the upper half of the intake nozzle shaft body 255 facing the first positioning circumferential groove 253a. A first O-ring 270 made of silicon rubber or the like that is sandwiched between the second positioning circumferential groove 255a having a concavely curved cross-section formed on the surface so as to be able to roll closely.
And a third positioning orbiting groove 255b having a concave cross section formed on the outer peripheral surface of the lower half of the intake nozzle shaft 255, and a cross section formed on the inner peripheral surface of the cylinder wall of the suction pad 260 so as to be opposed to the third positioning peripheral groove 255b. A second member made of silicon rubber or the like, which is sandwiched so as to be able to roll in close contact with the concavely curved fourth positioning circumferential groove 260b.
O-ring 280 and the outer peripheral step portion 25 of the lower mouth tubular portion 253.
3b and the compression coil spring 290 mounted on the upper spring receiver 260c of the suction pad 260.

The intake nozzle shaft 255 is the first O-ring 2
70 is suspended and supported by the support member 250 via 70, and the suction pad 260 is suspended and supported by the intake nozzle shaft body 255 through the second O-ring 280.
Due to the synergistic action of the two-stage O-rings, the swingability becomes more flexible than in the case of the first and second embodiments, and the first O-ring 270 and the second O-ring 280 are displaced. Stroke S of suction pad 260 is twice the sum of
Therefore, a light elastic stroke becomes longer than that of a single O-ring.

The initial elastic force of the compression coil spring 290 is initially reverse-deformed in the direction opposite to the forward direction in which the first and second O-rings 270 and 280 are displaced in close contact with each other due to the upward displacement of the adsorption pad 260 during adsorption. When set to a value that is the proportional limit of, the light elastic stroke can be doubled as compared with the case of a single O-ring.

[0037]

As described above, the vacuum gripping device according to the present invention has the following effects.

Since the concave curved surface of the second positioning circumferential groove makes rolling contact with the convex curved surface of the O-ring and the entire suction pad tilts around the O-ring, excessive crushing deformation of the O-ring is not caused. It is possible to obtain a flexible swinging flexibility. At this time, the compression coil spring exerts an urging force for swinging back. Further, since the O-ring is offset by the compression coil spring to the initial reverse deformation when not adsorbed, the upward stroke of the suction pad can be lengthened by the amount of displacement around the initial reverse deformation of the O-ring. Of course, since the suction pad can be made rigid or metallized, it can exert a vacuum suction function at high and low temperatures. Moreover, the support member and suction pad are conductively connected via a compression coil spring to prevent electrostatic discharge. Therefore, the O-ring itself does not have to be a conductive material. Therefore, the degree of freedom in selecting an O-ring made of a durable material is increased.

By adopting a configuration in which a plurality of O-rings sandwiched by the biconcave curved surfaces are connected in multiple stages, it is possible to further improve the swinging flexibility and lengthen the light elastic stroke.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view showing a main part of a vacuum gripping device according to a first embodiment of the present invention.

2 (a) to (c) are O in the vacuum gripping device.
It is an expansion schematic diagram which shows the transition of the mode around contact slip | deviation of a ring.

FIG. 3 is a graph showing the relationship between shear stress and shear strain of the contact ring displacement deformation of the O-ring.

FIG. 4 is a vertical cross-sectional side view showing a main part of a vacuum gripping device according to a second embodiment of the present invention.

FIG. 5 is a vertical sectional side view showing a main part of a vacuum gripping device according to a third embodiment of the present invention.

FIG. 6 is a side view showing a head portion of the IC test handler.

FIG. 7 is a side view showing a conventional vacuum gripping device partially broken away.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Test stand 2 ... IC socket 2a, 3a ... Lead pin 3 ... IC 5 ... IC test handler. 12 ... L-shaped arm 12a ... Horizontal end piece 14 ... IC positioning receiver 17 ... Intake holes 20, 40, 140, 240 ... Vacuum gripping device 18 ... Flexible intake pipe 22a ... Bolt part (mounting part) 60, 160, 260 ... Adsorption Pads 50, 150, 250 ... Bearing member 52 ... Intake passage 52a ... Intake port 62a ... Openings 56a, 156a, 253a ... First positioning circumferential grooves 66a, 166a, 255a ... Second positioning circumferential groove 54 ... Expanded diameter base 54b Outer peripheral step portion 56 ... Reduced diameter lower end portion 62 ... Pad portion 66 ... Upper mouth tubular portion 66b ... Upper spring receiver 70 ... O-rings 80, 180, 290 ... Compression coil spring 90 ... Adsorption target surface 150 ... Reduced diameter inner tubular portion 156 ... Lower mouth outer cylinder part 162, 260c ... Upper spring receiver 242a ... Intake port 242 ... Intake passage 251 ... Base part 252 ... Intake hole 253 ... Lower mouth cylinder part 253b ... Outer periphery Stepped portions 255 ... intake nozzle shaft member 255b ... third positioning circumferential groove 260b ... fourth positioning circumferential groove 266a ... opening 270 ... first O-ring 280 ... second O-ring g, _{G 1,} G 2 _... gap s, S ... stroke f 0 _... initial elastic force a ... forward b ... reverse

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) B25J 15/06 H01L 21/68

Claims (7)

(57) [Claims] 1. A swingable swingable suction device having a support member having an intake passage communicating with an intake port at the lower end and a mounting portion, and an opening directly below the intake port facing the intake port with a gap. A pad, a first positioning circumferential groove having a first curvature formed in the support member and having a substantially curved cross section, and a second positioning circumferential groove formed in the suction pad facing the first positioning circumferential groove at a distance. Elastic material having a substantially circular cross section having a curvature larger than the first and second curvatures, and is sandwiched between the second positioning circumferential groove having a substantially concave curvature and having a curvature of And a compression coil spring for applying an initial elastic force as a pre-load to the support member to the support member when the suction pad is not attracted. 2. The vacuum gripping device according to claim 1, wherein the support member has a diameter-expanded base portion and a reduced-diameter lower end portion integrally projecting downwardly in the axial direction and having the intake port.
The suction pad has a pad portion having the opening and an upper mouth cylinder portion which integrally projects with the pad portion and surrounds the reduced diameter lower end portion, and the first positioning circumferential groove is formed on the reduced diameter lower end portion. An outer peripheral groove formed on an outer peripheral surface, wherein the second positioning peripheral groove is an inner peripheral groove formed on an inner peripheral surface of the upper mouth cylinder portion, and the compression coil spring is formed on the enlarged diameter base portion and the upper mouth portion. A vacuum gripping device, characterized in that the vacuum gripping device is mounted between the upper part of the tubular part and the upper part. 3. The vacuum gripping device according to claim 1, wherein the support member has a reduced-diameter inner cylindrical portion having the intake port and a lower-portion outer cylindrical portion that surrounds the reduced-diameter inner cylindrical portion and projects downward. The pad is surrounded by the lower mouth outer cylinder portion, the first positioning circumferential groove is an inner circumferential groove formed on the inner circumferential surface of the lower mouth outer cylindrical portion, and the second positioning circumferential groove is the suction member. A vacuum gripping device, which is an outer peripheral groove formed on an outer peripheral surface of a pad, wherein the compression coil spring is mounted between the reduced-diameter inner cylinder portion and an upper portion of the suction pad. 4. The forward elastic force of the compression coil spring according to claim 1, wherein the initial elastic force of the compression coil spring is in the forward direction in which the O-ring closely contacts with the upward displacement of the suction pad during suction. A vacuum gripping device, wherein the vacuum gripping device is set to a value that is a substantially proportional limit of initial reverse deformation in the reverse direction. 5. A swingable swinging device comprising a support member having an intake passage communicating with the intake port at the lower end and a mounting portion, and an intake hole immediately below the intake port facing the intake port with a gap. An intake nozzle shaft, a suction swing pad having an opening directly below the intake hole and facing the intake hole with a gap, and a swingable movable suction pad, and a cross section having a first curvature formed on the support member. A concavely curved first positioning circumferential groove and a second positioning circumferential groove having a second curvature formed on the intake nozzle shaft body so as to face the first positioning circumferential groove at a distance. And a first O-ring made of an elastic material having a curvature larger than the first and second curvatures and having a substantially circular cross section, and formed on the intake nozzle shaft body. And a third positioning orbiting groove having a substantially curved cross-section having a third curvature And a fourth positioning circumferential groove having a fourth curvature and having a fourth curvature, which is formed in the suction pad so as to face the positioning circumferential groove at a distance from each other, and is sandwiched so as to be able to closely slip. The second O-ring made of an elastic material having a substantially circular cross section having a curvature larger than the third and fourth curvatures, and the suction pad is an axial downward force against the bearing member when the non-suction is performed, and the initial elastic force is set as a preload. A vacuum gripping device, comprising: a compression coil spring for applying. 6. The initial elastic force of the compression coil spring as set forth in claim 5, which is opposite to a forward direction in which the first and second O-rings are closely contacted with each other due to upward displacement of the suction pad during suction. A vacuum gripping device, wherein the vacuum gripping device is set to a value that is a substantially proportional limit of the initial reverse deformation of the direction. 7. An IC test handler, characterized by using the vacuum gripping device defined in any one of claims 1 to 6.