JPH08294846A - Indexing device - Google Patents

Abstract

PURPOSE: To provide an indexing device to be mounted on a machining center, etc., whereby an indexing shaft is located accurately in a plurality of positions at constant angular intervals while a low-cost fluid pressure cylinder is used. CONSTITUTION: A ratchet 14 is fixed onto an indexing shaft 12 supported on a device body 11, and four indexing pawls 16 are furnished on the periphery of the ratchet at a constant pitch. A pinion 17 is coupled with the indexing shaft 12 through a one-way clutch 21 and meshed with a rack 25 coupled with a piston 24 of a pneumatic cylinder 23 for indexing, and thereby the indexing shaft 12 is rotated intermittently in one direction at 90-deg. intervals. This pneumatic cylinder 23 and another pneumatic cylinder 43 for location are put under tuning control using a common pneumatic circuit. When the indexing shaft 12 is stopped, the piston rod 44 of the cylinder 43 is engaged by the front surface of the indexing pawl 16 so that the ratchet 14 is energized in the reverse direction, and the back surface of the pawl 16 is pressed to a stopper pin 31 perpendicularly intersecting the piston rod 44 so that the reverse rotation of the ratchet 14 is restricted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for indexing a work support table or the like of a machine tool, and more specifically, it uses a fluid pressure cylinder as an index drive source to index the index shaft into a plurality of equiangular positions. The present invention relates to an indexing device configured to be capable of being indexed.

[0002]

2. Description of the Related Art For example, as a table indexing device in a machining center, a technique using an electric servomotor as an indexing drive source is conventionally known. This conventional device has a random NC index function by a servo motor, and is configured so that the indexing shaft can be accurately indexed to any angular position within a range of 360 °.

[0003]

However, according to the conventional device, it is necessary to use an expensive servo motor and to equip a complicated control and operation system to operate the random NC index function. As a result, the price of the device becomes high and the size of the device becomes large. In particular, when the work is machined by indexing the table at 90 ° intervals, for example, the conventional apparatus uses only part of its precision indexing function. Therefore, the conventional device is too uneconomical and unsuitable for a user who frequently uses the equiangular indexing function.

Therefore, an object of the present invention is to provide a simple indexing device capable of accurately indexing the indexing shaft at a plurality of equiangular positions by using an inexpensive fluid pressure cylinder.

[0005]

In order to solve the above-mentioned problems, the indexing device according to the invention of claim 1 has an indexing shaft rotatably supported by the device body, and a ratchet wheel on the indexing shaft. , Indexing claws are formed at a plurality of positions that equally divide the outer circumference of the ratchet wheel, the pinion is connected to the indexing shaft via a one-way clutch, and a fluid pressure cylinder for indexing is provided on the device body. A rack that meshes with a pinion is connected to the piston of the cylinder, and the indexing shaft is configured to be intermittently rotatable in one direction at a slightly larger angle than the angle that equally divides the outer circumference of the ratchet wheel as the rack reciprocates. The device body has a positioning mechanism for holding the indexing shaft at the stop position. The positioning mechanism engages the back surface of the indexing pawl to restrict the reverse rotation of the ratchet wheel and the front surface of the indexing pawl. A biasing member that engages and biases the ratchet wheel in the opposite direction is provided.

An indexing device according to a second aspect of the present invention is configured by arranging the restricting member and the biasing member in a direction orthogonal to one indexing claw.

In the indexing device according to a third aspect of the present invention, the urging member includes a fluid pressure cylinder, and a common fluid pressure circuit that controls the cylinder and the fluid pressure cylinder for indexing is provided. It

[0008]

According to the invention of claim 1, the angle at which the outer circumference of the ratchet wheel is equally divided by the indexing shaft through the pinion and the one-way clutch with the reciprocating movement of the rack provided in the fluid pressure cylinder for indexing. It is intermittently rotated in one direction at a slightly larger angle. Therefore, the indexing shaft can be sequentially indexed into a plurality of positions at equal angles using an inexpensive fluid pressure cylinder. Further, when the indexing shaft is stopped, the ratchet wheel is non-rotatably clamped by the restricting member and the biasing member of the positioning mechanism, and the indexing shaft is reliably held at the stop position. At this time, the biasing member biases the ratchet wheel in the opposite direction to press the back surface of the indexing claw against the regulating member, so that the indexing shaft can be accurately positioned at each indexing position.

According to the second aspect of the present invention, since the restricting member and the biasing member are arranged in directions orthogonal to each other with respect to one indexing pawl, the installation space for the positioning mechanism is reduced and the apparatus main body is It is compactly constructed.

According to the third aspect of the present invention, since the indexing fluid pressure cylinder and the positioning fluid pressure cylinder are synchronously controlled by the common fluid pressure circuit, the indexing axis is indexed and positioned. The operation system of is easily configured.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows the entire machining center equipped with the indexing device of this embodiment. A machining head 2 is provided on a machine frame 1 of the machining center so as to be movable in X, Y, and Z directions, and a turntable 3 is installed below the machining head 2 so as to be rotatable in the normal and reverse directions within a range of 180 °. There is. Two index jigs 4 are mounted on the turntable 3, and each jig 4 is composed of an indexing device 5 and a work support table 6. Then, the work 7 is held by the holder 8 on the work support table 6, the work support table 6 is indexed by 90 ° at equal angular positions, and the work 7 is moved by a tool (not shown) of the machining head 2. It is possible to process all four surfaces with one chuck.

2 to 5 show the structure of the indexing device 5 in detail. The main body 11 of the indexing device 5 is formed in a rectangular box shape, and the work supporting table 6 is indexed therein. The indexing shaft 12 is rotatably supported by a bearing 13 about a horizontal axis. A ratchet wheel 14 is fixed on the indexing shaft 12 by a plurality of bolts 15, and four indexing claws 16 are formed on the outer periphery of the indexing shaft 12 at an equal pitch of 90 °, for example. The front surface (side surface in the clockwise direction in FIG. 3) of the indexing claw 16 is oblique to the tangent line of the ratchet wheel 14, and the rear surface (side surface in the counterclockwise direction) is formed to be substantially orthogonal.

A pinion 17 is fitted into the inner end of the indexing shaft 12, and is pressed against an end plate 20 integral with the indexing shaft 12 via a washer 19 by a disc spring 18 for preventing inertial rotation. A one-way clutch 21 is provided between the pinion 17 and the indexing shaft 12.
And the pinion 1 is actuated by the action of the clutch 21.
7 rotation in only one direction (clockwise in FIG. 4) is the indexing shaft 12
Is transmitted to

An indexing pneumatic cylinder 23 is horizontally provided integrally with the main body 11 at the top of the apparatus main body 11, and a piston 24 and a rack 25 are accommodated in the interior thereof so as to be integrally movable. The rack 25 is meshed with the pinion 17 via an opening 26 provided in the peripheral wall of the cylinder 23, and the opening 26 is sealed from the left and right by pistons 24 connected to both end surfaces of the rack 25. Then, with the reciprocating movement of the rack 25, via the pinion 17 and the one-way clutch 21,
The indexing shaft 12 is configured to be intermittently rotatable in one direction at an angle slightly larger than 90 ° which is equal to the pitch of the indexing claws 16.

A bracket 28 is provided on one side wall of the apparatus main body 11.
Are attached by bolts 29. Bracket 2
A stopper pin 31 as a regulating member is pivotally attached to the inward protruding piece 28a of 8 by a shaft 30 and is urged to rotate clockwise in FIG. 3 via a ball 33 by a spring 32 provided on the bracket 28. . Then, normally, the base end projection 31a of the stopper pin 31 is brought into contact with the bracket 28, the stopper pin 31 is held in the horizontal position, and the tip end thereof engages with the back surface of the indexing pawl 16 in the downward position to form the pawl. Car 14
The rotation in the opposite direction (counterclockwise in FIG. 3) is restricted. Further, when the indexing shaft 12 is rotated, the stopper pin 31 engages with the front surface of the indexing claw 16 to cause the indexing claw 16 to move.
Is pushed down to the outside of the rotation trajectory of. A spacer having an arbitrary thickness (generally a shim and a spacer) is provided between the main body 11 and the bracket 28 so that the engagement position between the stopper pin 31 and the indexing claw 16, that is, the stop position of the indexing shaft 12 can be finely adjusted. 34) is exchangeably interposed. The indexing shaft 12 is stopped at a position where the indexing claw 16 slightly passes through the tip of the stopper pin 31. In this case, the pinion 17 is the disc spring 18
Since it is pressed against the end plate 20 by the pinion 17,
The indexing shaft 12 is prevented from inertially rotating and overrunning when the rotation of the shaft is stopped.

A pneumatic cylinder 43 as a biasing member is provided on the apparatus main body 11 below the ratchet wheel 14. The pneumatic cylinder 43 and the stopper pin 31 are arranged in a direction orthogonal to the indexing pawl 16 in the downward position, and constitute a positioning mechanism 35 for holding the indexing shaft 12 in the stop position. . That is, the pneumatic cylinder 43 is provided with a piston rod 44 that can move up and down, and an engaging portion 44a that engages with the front surface of the indexing pawl 16 is obliquely cut out at the upper end thereof. Then, when the indexing shaft 12 is stopped, the piston rod 44 is pushed up inside the turning trajectory of the indexing pawl 16, and the engaging portion 44 a engages with the front surface of the indexing pawl 16.
The ratchet wheel 14 is biased in the opposite direction by the action of both inclined surfaces, the back surface of the indexing claw 16 is pressed by the stopper pin 31, and the indexing shaft 12 is positioned at the stop position. Further, when the indexing shaft 12 rotates, the piston rod 44 is pushed down, and the engaging portion 44 a is disengaged from the indexing pawl 16.

As shown in FIG. 5, the indexing device 5 is provided with a common pneumatic circuit 46 for synchronously controlling the pneumatic cylinder 23 for indexing and the pneumatic cylinder 43 for positioning. The pneumatic circuit 46 is provided with a fluid source (compressed air source) 47, a first conduit 48, a second conduit 49, and an electromagnetic switching valve 50. As shown in FIG. 4, a proximity switch 37 that detects the dog 36 on the end plate 20 and outputs an original position signal of the indexing shaft 12 and a dog 38 on the pinion 17 are detected in the device body 11. A proximity switch 39 for confirming the original position of the rack 17 (rack 25) and a proximity switch 41 for detecting the dog 40 on the pinion 17 and outputting a signal for switching the B position of the switching valve 50 are provided.

Next, the indexing device 5 configured as described above.
The operation of will be described. In the original position of the indexing device 5, the switching valve 50 is in the position B shown in FIG. 5, the piston 24 and the rack 25 of the pneumatic cylinder 23 for indexing, and the pinion 17 are in the position shown in FIG. The piston rod 44 of the pneumatic cylinder 43 and the stopper pin 31 are arranged at the positions shown in FIG. 3, respectively, and the indexing shaft 12 is held at the origin position. At this time, the proximity switches 37 and 39 detect the dogs 36 and 38, respectively, and confirm that the indexing shaft 12 and the pinion 17 are in their original positions.

In this state, when an indexing command is output from the NC device (not shown) of the machining center, the switching valve 50 is switched to the A position by the signal and the compressed air is supplied to the fluid source 4.
7 through the first circuit 48, and is supplied to the pressure chamber 23a of the indexing pneumatic cylinder 23 and the pressure chamber 43a of the positioning pneumatic cylinder 43. Then, in the positioning pneumatic cylinder 43, the piston rod 44 is pushed down, and the engaging portion 44 a thereof is disengaged from the indexing pawl 16. In synchronization with this, in the pneumatic cylinder 23 for indexing, the piston 2
4 and the rack 25 are moved forward, and the indexing shaft 12 is rotated together with the pinion 17. By rotating the ratchet wheel 14, the indexing claw 1
The front surface of 6 abuts on the stopper pin 31 and the stopper pin 3
1 is temporarily oscillated out of the rotation path of the indexing pawl 16.

When the pinion 17 is rotated to an angle slightly larger than 90 °, the stopper pin 31 moves to the spring 32.
As a result, the proximity switch 41 detects the dog 40 and turns on, and the switching valve 50 is switched to the B position. At this time, the compressed air passes through the second circuit 49 and is supplied to the pressure chamber 23b of the indexing pneumatic cylinder 23 and the pressure chamber 43b of the positioning pneumatic cylinder 43. Then
In the indexing pneumatic cylinder 23, the piston 24 and the rack 25 are returned, but the action of the one-way clutch 21 causes the pinion 17 to idle, so that the indexing shaft 12 rotates 90 ° from the origin position. Stopped in position.

On the other hand, in the positioning pneumatic cylinder 43, the piston rod 44 is pushed up and the engaging portion 44 is pushed.
The ratchet wheel 14 is non-rotatably clamped by "a" and the stopper pin 31, and the indexing shaft 12 is securely held at the stop position. At this time, the rear surface of the indexing pawl 16 is pressed against the stopper pin 31 with the engaging portion 44a biasing the ratchet wheel 14 in the opposite direction, so that the indexing shaft 12 can be accurately positioned at the indexing position. it can. Further, since the stopper pin 31 and the piston rod 44 are arranged in a direction orthogonal to the one indexing pawl 16, the installation space for the positioning mechanism 35 can be reduced and the apparatus body 11 can be made compact. There are also advantages.

In this way, when the indexing shaft 12 is positioned, the machining surface of the workpiece 7 on the workpiece support table 6 is machined by the tool of the machining head 2 in that state.
When this machining is completed and the next indexing command is output, the indexing shaft 12 is rotated at an angle of 90 ° in the same manner as described above and positioned at the next indexing position. Therefore, according to the indexing device 5 of the present embodiment, it is possible to index the indexing shaft 12 into four positions at an equal angle of 90 ° by using the inexpensive pneumatic cylinder 23. Further, since the pneumatic cylinder 23 for indexing and the pneumatic cylinder 43 for positioning are synchronously controlled by the common pneumatic circuit 46, one switching valve 50 reliably operates the two cylinders 23, 43. Therefore, the operation system for indexing and positioning the indexing shaft 12 can be greatly simplified. Since the indexing shaft 12 is locked at the indexing position by the engaging portion 44a, the pneumatic cylinder 23 for indexing may be a small one that rotates the indexing shaft 12.

The present invention is not limited to the above-mentioned embodiments, and as shown in the following examples, it is possible to embody the invention by arbitrarily changing the configuration of each part without departing from the spirit of the present invention. Is. (1) Applying the present invention to a vertical indexing device in which an indexing shaft is indexed around a vertical axis. (2) The pitch of the indexing claws is, for example, 30 °, 45 °, 6
Change to any angle such as 0 ° or 120 ° so that the indexing shaft can be indexed into a plurality of positions at an angle equal to the pitch of the indexing claw. (3) An intermediate shaft is provided between the rack and the pinion, and a one-way clutch is provided on the intermediate shaft. (4) Use hydraulic cylinders for the indexing fluid pressure cylinder and the biasing member of the positioning mechanism. (5) Arrange the regulating member and the urging member of the positioning mechanism so as to engage with the respective indexing pawls. (6) The indexing claw should be provided in a part of the position where the outer circumference of the ratchet wheel is equally divided, and not in other parts. (7) The turning angle of the indexing shaft by one actuation of the fluid pressure cylinder is set to be a size that is approximately an integer of the pitch angle of the indexing pawl. (8) The present invention provides a machine tool other than a machining center,
Or apply it to a device for indexing objects other than the work and embody it.

[0024]

As described above in detail, according to the first aspect of the invention, the indexing shaft is intermittently rotated in one direction by the fluid pressure cylinder so that the regulating member and the urging member of the positioning mechanism act. Since it is configured to be held at the stop position, it is possible to use an inexpensive fluid pressure cylinder to index the indexing shaft at a plurality of equiangular positions and to accurately position the indexing shaft at each indexing position. It has an excellent effect.

According to the second aspect of the invention, since the restricting member and the biasing member are arranged in directions orthogonal to each other with respect to one indexing claw, the installation space for the positioning mechanism can be reduced and the apparatus main body can be reduced. The effect is that it can be made compact.

According to the third aspect of the present invention, the fluid pressure cylinder for indexing and the fluid pressure cylinder for positioning are synchronously controlled by a common fluid pressure circuit, so that the indexing shaft is indexed and positioned. The operation system can be easily configured.

[Brief description of drawings]

FIG. 1 is a plan view of a machining center equipped with an indexing device of the present invention.

FIG. 2 is a vertical sectional view showing an embodiment of the indexing device.

3 is a cross-sectional view taken along the line AA of FIG.

4 is a partially cutaway left side view of FIG. 2. FIG.

FIG. 5 is a pneumatic circuit diagram of the indexing device.

[Explanation of symbols]

5 ... Indexing device, 6 ... Work support table, 11 ...
Device main body, 12 ... Indexing shaft, 14 ... Claw wheel, 16 ... Indexing claw, 17 ... Pinion, 21 ... One-way clutch, 2
3 ... Pneumatic cylinder for indexing, 24 ... Piston, 25
..Rack, 31..Stopper pin, 35..Positioning mechanism, 43..Pneumatic cylinder for positioning, 44..Piston rod, 46..Pneumatic circuit

Claims (3)

[Claims] 1. An indexing shaft is rotatably supported on the apparatus main body,
By fixing the ratchet wheel on the indexing shaft, forming indexing pawls at multiple positions that equally divide the outer circumference of the ratchet wheel, and connecting the pinion to the indexing shaft via a one-way clutch to index the device body. A fluid pressure cylinder is installed, a rack that meshes with the pinion is connected to the piston of the cylinder, and the indexing shaft is intermittently moved in one direction at a slightly larger angle than the angle that equally divides the outer circumference of the ratchet wheel as the rack reciprocates. It is configured to be rotatable, and the device main body includes a positioning mechanism that holds the indexing shaft at a stop position, and the positioning mechanism engages with the back surface of the indexing claw to restrict the reverse rotation of the ratchet wheel. An indexing device that engages with the front surface of the indexing claw and biases the ratchet wheel in the opposite direction. 2. The indexing device according to claim 1, wherein the restricting member and the urging member are arranged in a direction orthogonal to one indexing claw. 3. The biasing member includes a fluid pressure cylinder,
2. The indexing device according to claim 1, further comprising a common fluid pressure circuit for synchronously controlling the cylinder and the fluid pressure cylinder for indexing.