JPH0942224A - Spanworm type actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a simply constructed spanworm type actuator that steps pitch by pitch toward a guide member. SOLUTION: A casing 1 freely slidably engaged with a guide member (b) has a forward-motion stepping unit 41 incorporated into the backward-motion side half thereof and has a backward-motion stepping unit 42 incorporated into the forward-motion side half thereof. Each unit 41 , 42 comprises a stepping piston 40, a brake piston 41 located outwards of the piston 40, and a clamp member 42 located between the pistons, the brake piston 41 being pressed inwards by a pressure means 43 so as to hold the clamp member 42 under pressure to clamp the guide member (b). During forward or backward motion, fluid pressure is input to the stepping-piston pressure chamber 45 of the corresponding one stepping unit and to the brake-piston pressure chamber 44 of the other stepping unit, the clamp member 42 of the latter stepping unit is unclamped, and the casing 1 is made to step by the stroke of the piston 40 by means of the fluid pressure within the pressure chamber 45 of the former stepping unit while the stepping piston 40 of the unit serves as a reaction receiver.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scale-taker insect type actuator which moves relative to a guide member in steps of one pitch, and more particularly, holds a position of a work receiver on a jig and The present invention relates to an actuator suitable for a positioning drive device when changing according to a model.

[0002]

2. Description of the Related Art Conventionally, as a worm insect type actuator,
According to Japanese Patent Laid-Open No. 47-32631, a pair of casings that are extendably connected via a hydraulic jack are slidably engaged with a rod-shaped guide member, and each casing is used as a guide member. Incorporating a hydraulic brake unit that locks and unlocks the other, the brake unit of one casing is locked, the brake unit of the other casing is unlocked, and the other casing is stepped by the extension operation of the hydraulic jack. And then
With the brake unit of the other casing in the locked state and the brake unit of the one casing in the unlocked state, one casing is stepped to the other casing side by the contraction operation of the hydraulic jack, and the actuator is guided by repeating the above operation. It is known that a member is made to step toward one pitch along a member.

[0003]

By the way, in order to improve the responsiveness of control of the actuator, a valve for controlling oil supply / discharge to / from the hydraulic jack or the brake unit is attached to the casing, and the hydraulic jack or the brake unit and the valve are attached. It is desirable to reduce the fluid path length between and as short as possible.

In the above-mentioned conventional example, since the hydraulic jack can be integrated in one casing, a valve block having a valve for a brake unit and a valve for the hydraulic jack built in the casing can be attached to the casing.
Fluid pressure can be input to the brake unit and the hydraulic jack via each valve by a common piping member connected to the valve block, but since the other casing moves relative to the one casing, it is built in the other casing. When the valve for the second brake unit is housed in the valve block attached to the one casing, the valve block and the second brake unit have no choice but to be connected via a flexible hose, and the second brake unit has to be connected. The control response of the unit deteriorates, and bending and stretching of the flexible hose accompanying relative movement of the other casing causes fatigue of the hose, resulting in poor durability.

In this case, it is conceivable to attach the valve for the second brake unit to the other casing, but in this case, the piping member connected to the pressure source is separately provided on one casing side and the other casing side. It is necessary to handle the piping, which makes the piping troublesome.

Furthermore, in the above-mentioned conventional example, since the actuator is composed of two casings that move relative to each other,
Only a part of the actuator (one of the two casings) can be used as a fixed part of the driven object such as a work receiver, which impairs the rigidity and accuracy of positioning the driven object.

Further, in the above-mentioned conventional example, since the step is carried out at the pitch corresponding to the stroke of the hydraulic jack in any of the reciprocating movements, the stepping pitch in the forward movement and the stepping pitch in the backward movement are When the actuator is used as a positioning drive device for the workpiece receiver on the jig, the position of the workpiece receiver can be changed only at a pitch that is an integral multiple of the stepping pitch, which impairs the degree of freedom of position change. Further, in the above-mentioned conventional example, since a pair of brake units and a hydraulic jack for stepping are required, the structure becomes complicated.

In view of the above points, the present invention enables simplification of the handling of the piping member by enabling the stepping using a single casing, and the rigidity of positioning the driven object. The object of the present invention is to provide a simple insect-worm type actuator having a simple structure, which is capable of ensuring the accuracy and differentiating the step pitch in the forward movement and the step pitch in the backward movement.

[0009]

In order to achieve the above object,
The present invention is a shingled insect type actuator that moves relative to a guide member, and is assembled in a longitudinal direction of the guide member, which is slidable with respect to the guide member, and a half portion on the backward direction side of the casing. A step unit for forward movement,
The stepping unit for backward movement is attached to the forward half of the casing, and each stepping unit is arranged outside the longitudinal direction of the casing with respect to the stepping piston and the stepping piston. A brake piston, a clamp member that is interposed between the stepping piston and the brake piston, and that clamps the guide member when the piston is pinched, and the brake piston in the longitudinal direction of the casing. A first pressure chamber for pushing the braking piston outward in the longitudinal direction of the casing, and a second pressure chamber for pushing the stepping piston outward in the longitudinal direction of the casing. , Fluid pressure is input to the second pressure chamber of the forward step unit and the first pressure chamber of the backward step unit during forward step, and the second pressure chamber of the backward step unit during backward step And the forward step unit Providing a fluid supply means for inputting a fluid pressure to the first pressure chamber and, wherein the.

Normally, the braking piston of each stepping unit is urged inward in the longitudinal direction of the casing by the urging means, and the clamp member is clamped between the stepping piston and the stepping piston located at the inner stroke end position. It will be clamped. In this state, the thrust force acting on the casing in the forward direction is received by the clamp member via the stepping piston of the backward stepping unit, and the thrust force in the backward direction is received by the forward stepping unit. The clamping member is received through the stepping piston of the above and the casing is locked in place.

When a fluid pressure is input to the first pressure chamber of the backward stepping unit, the brake piston of the backward stepping unit recedes outward against the biasing means, and the backward stepping unit of the backward stepping unit moves. The clamp member is in the unclamped state, and the casing can move in the forward direction. On the other hand, since the clamp member of the forward motion stepping unit is maintained in the clamped state, when fluid pressure is input to the second pressure chamber of the forward motion stepping unit, the forward motion piston is moved to the casing by receiving the reaction force. The pressing force in the direction acts, and the casing steps in the forward direction by the stroke of the stepping piston.

After this stepping, both the first pressure chamber of the backward stepping unit and the second pressure chamber of the forward stepping unit are opened to the atmosphere. According to this, the clamp member of the backward stepping unit is released. While in the clamped state, the stepping piston of the forward stepping unit is pushed back to the inward stroke end position while moving relatively to the casing by the urging force from the braking piston, and returns to the original state. Then, by repeating the above-described operation, the casing steps in the forward movement direction for one pitch with the stroke of the forward movement piston of the forward movement stepping unit.

Even when a fluid pressure is input to the first pressure chamber of the forward step unit and the second pressure chamber of the backward step unit, the casing operates as the backward step unit by the same operation as described above. Step in the backward direction by the stroke of the advancing piston. In this way, since the forward movement and the backward movement are performed by using different step units, it is possible to make a difference between the forward step and the backward step.

Further, since the casing is single, the valve block, which constitutes the fluid supply means and incorporates the valve for the first pressure chamber and the valve for the second pressure chamber of each step unit, is installed in the casing. Fluid pressure can be input to each unit with high responsiveness from a common piping member that is mounted and connected to the valve block, and the handling of the piping member with respect to the actuator is simplified. Further, since the actuator is composed of a single casing, the entire actuator can be used as a fixed part of the driven object, and the rigidity and accuracy of positioning the driven object are secured. Further, since only one pair of step units is provided, the structure is simpler than that of a conventional actuator having one pair of brake units and step hydraulic jacks.

The first pressure chamber and the second pressure chamber of each step unit
Since the pressure chambers are respectively arranged inward in the longitudinal direction of the casing with respect to the brake piston and the stepping piston, the fluid supply means can be centrally arranged near the central portion of the casing, which is advantageous.

Various types of clutch members are conceivable, but the clamp member may be a disc spring-like member whose inner diameter is reduced when the clamp member is clamped between the stepping piston and the brake piston. If so, the structure becomes simple. Further, if the clamp member is configured to include a collet chuck that is externally inserted to the guide member, durability is improved and the constraint force for the guide member can be increased, which is advantageous.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an arrangement portion of a work receiver on a jig used in an automobile manufacturing line or the like, in which a rod-shaped guide member b is horizontally provided on a jig main body a and a guide member b is provided. A work receiver c, which is a driven object, is attached to an actuator A that moves left and right along the structure, and the position of the work receiver c can be changed according to the model of the work.

The actuator A is provided with a casing 1 slidably engaged with a guide member b, a valve block 2 is attached to the outer surface of the casing 1, and a pipe member 3 connected to the valve block 2 is connected to the valve block 2. A pressure fluid such as compressed air is supplied to actuate the actuator A by air pressure.

The details of the actuator A are as shown in FIG. 2. The stepping unit 4 ₁ for right movement is incorporated in the left half of the cylindrical casing 1 slidably fitted on the guide member b. A stepping unit 4 ₂ for left movement is incorporated in the right half of the casing 1.

[0020] Migidoyo stepping unit 4 _1, the stepping piston 40, outer longitudinal side of the casing 1 to increment piston 40, i.e., the brake piston 41 disposed to the left, for stepping Piston 40 and brake piston 41
A clamp member 42 that is interposed between the guide member b and the brake member 41, and a biasing means 43 that biases the brake piston 41 inward in the longitudinal direction of the casing 1, that is, to the right.
And a first pressure chamber 44 that pushes the brake piston 41 to the left and a second pressure chamber 45 that pushes the stepping piston 50 to the left. The urging means 43 is composed of a coil spring, but it may be composed of an air spring or the like.

The brake piston 41 is integrally formed with a collar 41a extending rightward through the partition wall 10 fixed to the casing 1 defining the first pressure chamber 44 therebetween. As shown in FIG. 3, the clamp member 42 is composed of a disc spring-shaped member 100 in which radial slits extending from the inner peripheral side to the middle of the radial direction are formed. 41 color 41a
And the stepping piston 40 was brought into contact with the right side surface of the outer peripheral portion of the member 100. And the stepping piston 40
However, the urging means acting through the brake piston 41 in a state of being in contact with the central partition wall 11 of the casing 1 that defines the second pressure chamber 45 between them and at the inner stroke end position. The disc spring-like member 100 is pinched between the stepping piston 40 and the inner diameter of the disc spring-like member 100 by the biasing force of 43, the inner peripheral edge of the member 100 bites against the guide member b, and the clamp member 42 The guide member b is held in a clamped state.

A stopper 1 is provided at the outer end of the casing 1 for restricting the outward retreat position of the brake piston 41.
2 are provided. Further, although the clamp member 42 is arranged on the stepping piston 40 side in the present embodiment, the clamp member may be arranged on the brake piston side, and the stepping piston may be provided with a collar that abuts against the clamp member. .

[0023] Hidaridoyo stepping unit 4 _2, the only structure itself 4 ₁ and directional Migidoyo stepping unit are opposite the same, the same components as Migidoyo stepping unit 4 ₁ The same reference numerals are given and their explanations are omitted.

In the valve block 2 mounted on the casing 1, the pressure chambers 44, 4 of the step unit 4 ₁ for right movement are installed.
5, the valves 20 ₁ and 21 ₁ connected to the air supply / exhaust ports 44a and 45a, and the pressure chambers 4 of the left motion stepping unit 4 _2.
The valves 20 ₂ and 21 ₂ connected to the supply / exhaust ports 44a and 45a of 4, 45 are provided. Each of these valves 20 ₁ , 20 ₂ , 21 ₁ and 21 ₂ is composed of a solenoid valve, and is switched and controlled by a signal from a controller (not shown). Further, the air supply ports 20a, 21a and the exhaust ports 20b, 21b of the respective valves 20 ₁ , 20 ₂ , 21 ₁ , 21 ₂ are
A common pipe member 3 and a silencer 24 are provided through the manifold passages 22 and 23 for air supply and exhaust in the valve block 2, respectively.
Connected to. In addition, each valve 20 ₁ ,
Even when 20 ₂ , 21 ₁ and 21 ₂ are individually attached, a manifold can be attached to the casing 1 to supply air to the valves 20 ₁ , 20 ₂ , 21 ₁ and 21 ₂ from the common piping member 3. .

In this embodiment, the pressure chambers 44 and 45 are arranged inward of the corresponding pistons 40 and 41 in the longitudinal direction of the casing 1, and as a result, the pressure chambers 44 and 45 are arranged. The supply / exhaust ports 44a and 45a can be centrally arranged near the center of the casing 1, and the valve block 2 can be downsized.

Next, the operation of the actuator A will be described. Normally, RyoAyumiSusumu unit 4 _1, 4 first ₂ and the second of the two pressure chambers 44 and 45 are open to the atmosphere together RyoAyumiSusumu unit 4 _1, 4 ₂ of stepping piston in this state 40,
40 together resides both in the stroke end position of the inner, RyoAyumiSusumu unit 4 _1, 4 ₂ of the clamp member 42 clamps the guide member b together. In this case, a thrust force to the left which act via the workpiece receiving c to the actuator A, the clamping member via the center wall 11 of the casing 1 and Migidoyo incremented unit 4 _first stepping piston 40 received at 42, also, the thrust force to the right is received in the clamping member 42 through the said partition wall 11 and Hidaridoyo stepping unit 4 _second stepping piston 40 of the casing 1, and thus, Actuator A is locked in place.

The time of the actuator A is shifted rightward, first, inputs the air pressure in the second pressure chamber 45 of Migidoyo stepping unit 4 _1. In this case, stepping piston 40 of the walking advance unit 4 ₁ from being locked relative to the guide member b via the clamping member 42, the casing 1 by the reaction force due to the air pressure in the second pressure chamber 45 Pressed to the right. Also enter the air pressure in the first pressure chamber 44 of Hidaridoyo stepping unit 4 ₂ in this state. According to this, it retracted outwardly against the bias means 43 brake piston 41 of Hidaridoyo stepping unit 4 _2, the walking proceeds unit 4 _second clamp member 42
Becomes an unclamped state, the casing 1 becomes movable to the right, and the second pressure chamber 4 of the right-moving step unit 4 ₁ is moved.
The air pressure in the 5, Migidoyo stepping unit 4 _first stepping piston 40 the actuator A is as shown in FIG. 4 (a)
Step to the right by the stroke of. Although the stroke of the stepping piston 40 in abutment of the stopper 12 to the brake piston 41 of Migidoyo stepping unit 4 ₁ in the illustrated example is restricted, in abutment of the partition wall 10 to the clamping member 42 The stroke may be restricted.

[0028] When the actuator A as described above is incremented, first, the first pressure chamber 44 of Hidaridoyo stepping unit 4 ₂ opened to the atmosphere, as shown in FIG. 4 (b), of the walking advance unit 4 ₂ switching the clamping member 42 in a clamped state, then the second pressure chamber 45 of Migidoyo stepping unit 4 ₁ is opened to the atmosphere. According to this, the clamp member 42 of the step unit 4 ₁ is switched to the unclamped state, and the urging means 4 acting on the brake piston 41 of the step unit 4 ₁ is operated.
By the urging force of 3, the stepping piston 40 is pushed back to the inner stroke end position while moving relatively to the casing 1 and the guide member b via the clamp member 42, and the state shown in FIG. 2 is restored.

[0029] Then, the casing 1 by repeating the operation described above is incremented to 1 pitch addressed right in the stroke of the stepping piston 40 of Migidoyo stepping unit 4 _1. If the air supply and exhaust in Migidoyo stepping unit 4 first pressure chamber 44 ₁ and Hidaridoyo incremented unit 4 of the _second pressure chamber 45, by the action similar to the above, the casing 1 is Hidaridoyo increment unit 4 ₂ With the stroke of the stepping piston 40, a step is made to the left toward one pitch.

Here, in the illustrated example, the strokes of the stepping pistons 40 of the stepping units 4 ₁ and 4 ₂ are set to be equal, but if the strokes are different, the position of the work receiver c is considerably increased. You will be able to change it with great freedom. For example, 5 mm piston stroke of Migidoyo stepping unit 4 _1, by setting the piston stroke of Hidaridoyo stepping unit 4 ₂ to 2 mm, 2 to the left by 1 KaiAyumiSusumu rightward KaiAyumiSusumu By doing so, the work receiver c can be displaced to the right by 1 mm, and the position can be changed at a finer pitch than the piston stroke.

By the way, in the above-mentioned embodiment, the clamp member 42 is constituted by the disc spring member 100. However, as in the embodiment shown in FIG. 5, the collet chuck 101 externally fitted to the guide member b is replaced by the disc spring member 100. The clamp member 42 may be configured by fitting to the inner circumference of the. In the illustrated example, the collet chuck 101 is the collar 4 of the brake piston 41.
It is integrated with 1a.

Further, as shown in FIG. 7, the clamp member 42 is divided into a plurality of segment plates 1 divided in the circumferential direction.
It is also possible to configure with 02. In this case, as shown in FIG. 6, the stepping piston 4 is mounted on the segment plate 102 via a retainer ring 103 that supports the outer edge of the segment plate 102.
Contact 0. According to this, when the clamp member 42 is pinched between the step-up piston 40 and the brake piston 41, the segment plate 102 stands up in the radial direction by using the retainer ring 103 as a radial reaction force receiver. And the inner edge part bites into the guide member b.
Incidentally, as in the embodiment shown in FIG.
The segment plate 102 and the collet chuck 101 may be combined.

Further, the clamp member 42 can be constituted by a ball type collet chuck 104 as shown in FIG. The chuck 104 includes an outer race 104a having an inner peripheral surface tapered, a collet-shaped inner race 104b having an outer peripheral surface tapered, and a ball 104c interposed between the races 104a and 104b.
And the outer races 104a and 104b are connected by a pair of end pieces 104d and 104d at both ends so as to be relatively movable in the axial direction.
When the inner race 104b and the inner race 104b are pinched in the direction of the arrow between the stepping piston and the braking piston, the ball 104c
The inner race 104b is reduced in diameter through the guide so that the guide member b is clamped. In the figure, 104e is a ball retainer.

As described above, various clamp members 42 are conceivable. However, in order to reduce the number of parts and reduce the cost, it is desirable to use the disc spring member 100. Further, the cost and durability can be reduced. The combination of the disc spring-shaped member 100 and the collet chuck 101 is advantageous in achieving compatibility with the properties. Further, in the above embodiment, air is used as the working fluid of the actuator A, but liquid such as oil can be used.

[0035]

As is apparent from the above description, according to the present invention, a pair of step units for forward movement and backward movement incorporated in a single casing are used to walk in the forward movement direction and the backward movement direction. Since the actuator structure is simplified and the fluid pressure can be supplied by distributing it from the common piping member to each unit on the casing, it is possible to simplify the handling of the piping member for the actuator. In addition, since the entire actuator can be used as the fixed part of the driven object, the rigidity and accuracy of positioning of the driven object can be ensured. Further, the fluid supply means is centrally arranged in the casing to provide the fluid supply means. Can be made compact, and since the step pitch can be made different between the forward movement and the backward movement, the degree of freedom in changing the position of the driven object can be increased.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of use of the actuator of the present invention.

FIG. 2 is a cutaway side view of a first embodiment of the actuator of the present invention.

FIG. 3 is a front view of a disc spring member used as a clamp member in the first embodiment.

4 (a) and 4 (b) are views showing the operation of the first embodiment.

FIG. 5 is a cutaway side view of the second embodiment.

FIG. 6 is a cutaway side view of the third embodiment.

FIG. 7 is a front view of a segment plate used as a clamp member in the third embodiment.

FIG. 8 is a cutaway side view of the fourth embodiment.

FIG. 9 is a sectional view of a ball-type collet chuck used as a clamp member.

[Explanation of symbols]

A actuator b guide member 1 casing 2 valve block (fluid supply means) 4 ₁ , 4 _{2 step} unit 40 step piston 41 brake piston 42 clamp member 43 biasing means 44 first pressure chamber 45 second pressure chamber 100 Belleville spring member 101 Collet chuck

Claims (3)

[Claims] 1. A worm insect actuator that moves relative to a guide member, the casing being slidably engaged with the guide member and slidable with respect to the guide member in the longitudinal direction of the guide member. The step unit for forward movement assembled to the half portion on the backward movement side of the casing, and the stepping unit for backward movement attached to the half portion on the forward movement direction side of the casing, each stepping unit, A stepping piston, a brake piston arranged outside the stepping piston in the longitudinal direction of the casing, and a pinching force provided between the stepping piston and the brake piston. A clamp member that clamps the guide member when the brake piston moves, a biasing unit that biases the brake piston inward in the longitudinal direction of the casing, and a first member that presses the brake piston outward in the longitudinal direction of the casing. A force chamber and a second pressure chamber that presses the stepping piston outward in the longitudinal direction of the casing, the second pressure chamber of the forward stepping unit and the first of the backward stepping unit during the forward step. Fluid supply means is provided for inputting fluid pressure to the pressure chamber and for inputting fluid pressure to the second pressure chamber of the backward step unit and the first pressure chamber of the forward step unit during backward step. A shakudori insect type actuator. 2. The clamp member is formed of a disc spring-like member whose inner diameter is reduced when the clamp member is pinched between the stepping piston and the brake piston. The worm-type actuator described in. 3. The worm insect actuator according to claim 1, wherein the clamp member includes a collet chuck that is externally inserted into the guide member.