JPH11188560A - Cam type automatic tool changing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten the overall length of a turret by eliminating bearings for supporting a turret so as to miniaturize a device. SOLUTION: A device comprises a first cam mechanism 30 which makes an arm shaft 2 to perform an intermittent rotational motion, a second cam mechanism 40 which makes the arm shaft 2 to perform a repeated linear motion, and an electric motor 50 for driving these cam mechanisms. In this case, a pair of holding mechanism 71 and 71' which hold a roller gear 4 not engaged with the first cam mechanism 30 at least from both axial sides of the arm shaft and restrict the axial movement of a turret 3' by taking a support reaction against a housing 1 and a bush 63 for rotatably supporting the turret 3' are provided. Thus, bearings for supporting the turret 3' are not required to reduce the overall length of the turret 3' so as to nuniaturige the device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic tool changer (automatic tool changer) for automatically changing a rotary cutting tool or the like.
In particular, the present invention relates to a cam-type automatic tool changer that uses a cam mechanism to perform a movement required for tool change on an arm shaft.

[0002]

2. Description of the Related Art Conventionally, in order to transfer a tool between a machine tool and a tool magazine, a composite motion combining an intermittent rotation motion and a repetitive linear motion is performed on an arm shaft using two cam mechanisms. There is known a cam-type automatic tool changer (see Japanese Patent Publication No. 63-65465).

FIGS. 3 and 4 show a conventional cam-type automatic tool changer, in which an arm shaft 2 supported in a housing 1 so as to be rotatable about an axis and slidable in an axial direction, and attached to the arm shaft 2. First cam mechanism 30 for performing intermittent rotation
A second cam mechanism 40 for causing the arm shaft 2 to perform a linear motion repeatedly;
It is composed of an electric motor 50 for driving the zero.

The configuration of each part will now be described. First, a cylindrical turret 3 is spline-fitted on the upper part of the arm shaft 2, and the arm shaft 2 can move relative to the turret 3 in the axial direction. However, relative rotation is impossible around the axis. A plurality of roller gears 4 which are engaged with a cam groove of a roller gear cam 31 described later are provided radially and at equal intervals on the outer periphery of the lower portion of the turret 3, and the upper portion of the turret 3 is connected via a pair of tapered roller bearings 5, 5 '. And is rotatably supported on the inner periphery of a boss 6 fixed to the upper wall of the housing 1.

On the other hand, an annular groove 7a is formed at the center of the arm shaft 2 between a pair of flanges 7, and a roller 47 of a second lever 46 described later is engaged with the annular groove 7a. I have. The lower part of the arm shaft 2 is rotatably supported on the inner periphery of a boss 9 fixed to the lower wall of the housing 1 via a bush 8.

With such a configuration, the arm shaft 2 rotates integrally with the turret 3 when a rotational force acts on the turret 3 via the roller gear 4. In this state, an axial force is applied from the flange portion 7. When actuated, it can also move in the axial direction.

[0007] At the upper end of the arm shaft 2 are provided a spring 10 for balancing and an extension shaft portion 11 for supporting the spring, and a protective cover 12 for covering them is attached to the upper surface of the housing 1. ing.

On the other hand, at substantially the center of the housing 1, a roller gear cam 31 having a rotation axis 13 perpendicular to a plane including the rotation axis of the arm shaft 2 and a cam wheel 41 are provided so as to rotate coaxially and integrally.

A plurality of cam grooves (not shown) are formed on the outer periphery of the roller gear cam 31, and a roller gear 4 provided on the outer periphery of the turret 3 is engaged with the cam grooves. That is, when the roller gear cam 31 constitutes the first cam mechanism 30 and the roller gear cam 31 rotates at a constant speed, the movement is transmitted to the turret 3 via the roller gear 4 guided by the cam groove, so that relative rotation becomes impossible. The arm shaft 2 performs an intermittent rotational movement.

A plurality of teeth meshing with the worm gear 53 are formed on the outer periphery of the cam wheel 41, and a cam groove (not shown) whose distance from the center of rotation is formed on the end surface of the cam wheel 41. The roller 43 of the first lever 42 is engaged with the cam groove. That is, when the cam wheel 41 forms a second cam mechanism 40 and the cam wheel 41 rotates at a constant speed, the first lever 42 swings about the pin 44 by the roller 43 guided by the cam groove. Move, and the second lever 46
Makes a rocking motion about the pin 48. Further, this movement is transmitted to the flange portion 7 of the arm shaft 2 via the roller 47 of the second lever 46, so that the arm shaft 2 performs repeated linear movement in the axial direction.

An electric motor 50 for driving these cam mechanisms is provided on the upper surface of the housing 1. The rotation of the electric motor 50 is transmitted to a worm gear 53 via an output shaft 51, a gear box 52 and the like. The cam wheel 41 meshing with the cam wheel 41 and the roller gear cam 31 provided integrally therewith rotate.

With this configuration, when the electric motor 50 is driven, the roller gear cam 31 and the cam wheel 41
Are integrally rotated at a constant speed, the constant speed rotational motion of the roller gear cam 31 is transmitted as an intermittent rotary motion of the arm shaft 2, and the constant speed rotary motion of the cam wheel 41 is transmitted as a repeated linear motion of the arm shaft 2, respectively. The shaft 2 performs a combined motion combining these.

[0013]

However, such a conventional apparatus has the following problems.

First, since the upper portion of the turret 3 is supported via a pair of tapered roller bearings 5 and 5 ', the turret 3 becomes longer in the axial direction, causing an increase in the size of the apparatus. Tapered roller bearing 5, 5 '
In order for the roller gear cam 31 and the like not to interfere with each other, it is necessary to arrange them at some distance from each other, and there is a limit to miniaturization of the apparatus.

The turret 3 receives a force from the roller gear engaging portion. However, since the position where these forces act and the position where the turret 3 is supported are separated, the force acting on the turret 3 in the bending direction increases. Therefore, it was necessary to increase the rigidity by increasing the thickness of the turret or to increase the strength of the supporting bearing.

Further, since the turret 3 and the arm shaft 2 are spline-fitted, a plurality of teeth extending in the axial direction are formed on the outer periphery of the arm shaft 2 and corresponding grooves are formed on the inner periphery of the turret 3. Although it was necessary to form such spline teeth and grooves, a special tool such as a spline hob and a spline broach was required, and it could not be processed with a normal cutting tool.

SUMMARY OF THE INVENTION The present invention has been made in view of such problems of the conventional apparatus, and has as its object to reduce the overall length of the turret to reduce the size of the apparatus and to facilitate machining of an arm shaft and the like. I do.

[0018]

According to a first aspect of the present invention, there is provided an arm shaft supported in a housing so as to be rotatable about an axis and slidable in the axial direction, and the arm shaft is slidable in an axial direction and relatively movable. A turret fitted non-rotatably, a plurality of roller gears provided on the outer periphery of the turret, a first cam mechanism which engages with the roller gears to cause the turret and the arm shaft to perform intermittent rotation, and engages with the arm shaft. In a cam type automatic tool changer including a second cam mechanism for performing repetitive linear motion and an electric motor for driving the cam mechanisms, the cam type automatic tool changer is engaged with a first cam mechanism among the plurality of roller gears. A pair of pinching members that pinch the roller gear from both sides in the axial direction of the arm shaft and take a supporting reaction force on the housing to restrict the axial movement of the turret; It is characterized in that a bushing for rotatably supporting the.

According to a second aspect of the present invention, in the first aspect, the holding member is a horseshoe-shaped member having an open part, and is fixed to the inner wall of the housing so as to be exchangeable with a bolt from the axial direction of the arm axis. Is what you do.

In a third aspect based on the first or second aspect, the roller gear comprises a plurality of pins rotatably supported by holes provided on the outer periphery of the turret and projecting a predetermined length outside the turret. It is characterized by comprising.

According to a fourth aspect of the present invention, in the first to third aspects, some of the plurality of pins also protrude inside the turret, and the pins protruding inside the turret are formed on the outer periphery of the arm shaft. The turret and the arm shaft are configured so as to be unable to rotate relative to each other by engaging with a plurality of rectangular cross-sectional grooves extending in the axial direction.

[0022]

According to the first aspect of the present invention, the axial force acting on the turret can be received by a pair of holding members sandwiching the roller gear, and the force perpendicular to the axis can be received by the bush. The provided turret support bearing is not required, and the apparatus can be downsized.

Further, since the bush having a small thickness does not easily interfere with the roller gear cam and the like and can be provided in the vicinity of the roller gear engaging portion, the roller gear engaging portion and the turret supporting portion can be brought close to each other, thereby reducing the overall length of the turret. can do.

Further, since the roller gear engaging portion and the turret supporting position are close to each other, the force in the bending direction acting on the turret can be suppressed. Thereby, the rigidity required for the turret is reduced, and the turret can be thinned.

According to the second aspect of the present invention, since the holding member is a horseshoe-shaped member having a partially opened portion, the axial movement of the turret can be reliably restricted while preventing interference with the cam mechanism. Furthermore, since the horseshoe-shaped members are replaceably mounted on the inner wall of the housing, even when these members are worn, they can be easily replaced, and the maintainability can be improved.

According to the third aspect of the present invention, since the roller gear is composed of a plurality of pins, the diameter of the gear (pin) is smaller than that of the conventional roller gear, so that the size of the roller gear cam having the cam groove engaged with the gear is reduced. be able to.

According to the fourth aspect, the groove formed on the outer periphery of the arm shaft is different from the spline groove, and is a rectangular groove having a constant groove width in the depth direction. Becomes easier.

[0028]

Embodiments of the present invention will be described below with reference to the accompanying drawings. Since the overall configuration of the apparatus is almost the same as the conventional one shown in FIGS. 3 and 4,
The same portions are denoted by the same reference numerals, and a description will be given mainly of the structure around the upper portion of the arm shaft and the turret, which is a feature of the present invention.

FIG. 1 and FIG. 2 show an embodiment of the present invention.

To explain this, three grooves 61 extending in the axial direction are formed in the upper part of the arm shaft 2, and the arm shaft 2 is slidably fitted to the cylindrical turret 3 '. I have. This groove 61 has a rectangular cross section having a constant groove width in the depth direction, unlike a normal spline groove.

A boss 64 is fixed to the upper wall of the housing 1, and the boss 64 protrudes toward the inside of the housing to near the roller gear engaging portion. An upper part of the turret 3 ′ is rotatably supported on a lower inner periphery of the boss 64 via a bush 63. Only a part of the lower end of the boss 64 and the bush 63 on the roller gear cam 31 side is short and tapered, so that the cam mechanism does not interfere with the boss 64 or the bush 63 even when these members are brought close to the roller gear engaging portion. I have.

In the large diameter portion at the lower part of the turret 3 ', six holes 65a, 65 penetrating the turret 3' vertically in the axial direction.
b, 65c, 66a, 66b, 66c are formed concentrically and at equal intervals.

Of the six holes, holes 65a, 65b,
A long pin 68 is rotatably supported by a pin 65c via a pin holder 67, and the remaining holes 66a, 66b, 66c
A short pin 69 is also rotatably supported via a pin holder 67. A collar 70 is provided in the middle of each pin, and the collar 70 comes into contact with the pin holder 67 from the inside, so that each pin does not fall out of the turret 3 '.

At this time, the long pins 68 protrude outside the turret 3 ′ by a predetermined length and also protrude inside the turret 3 ′, and engage with the grooves 61 formed on the outer periphery of the arm shaft 2. In combination, the relative rotation between the turret 3 'and the arm shaft 2 is restricted.

On the other hand, the short pin 69, like the long pin 68, protrudes outside the turret 3 'by a predetermined length, but does not protrude inside the turret 3', but only comes into contact with the outer periphery of the arm shaft 2. .

The pins 68 and 69 constitute the roller gear 4, and when the roller gear cam 31 rotates, it sequentially engages with a cam groove formed on the outer periphery thereof. The number of the pins 68, 69 is not limited to this, and the pins 68, 69 function as the roller gear 4, and the turret 3 'and the arm shaft 2
The number may be larger or smaller as long as it is a number sufficient to regulate the relative rotation of.

On the other hand, the pins 68 and 69 and the roller gear cam 3
A pair of engaging members 71 and 71 ′ are provided on the inner wall of the housing 1 on the opposite side of the arm shaft 2 from the engaging portion with the bolt 1.
At 2, 72 ', it is exchangeably fixed at a predetermined position on the inner wall of the housing.

The engaging members 71, 71 'are formed in a horseshoe shape with a part opened on the roller gear cam 31 side so as not to interfere with the roller gear cam 31 or the like.
The pins 68, 69 which are not engaged with the turret 3 are sandwiched from both sides in the axial direction of the arm to restrict the axial movement of the turret 3 '. Here, the engaging members 71 and 71 'are separate members on the upper side and the lower side, but they may be integrated parts.

Next, the operation will be described.

When the electric motor 50 is driven, the roller gear cam 31 and the cam wheel 41 integrally rotate at a constant speed. The rotation of the roller gear cam 31 is performed by the pins 68 and 69 which engage with the cam grooves formed on the outer periphery. The arm shaft 2 performs an intermittent rotating motion. On the other hand, the rotation of the cam wheel 41 is controlled by a first lever 42 having a roller 43 which engages with a cam groove formed on the end face thereof,
The power is transmitted to the flange portion 7 of the arm shaft 2 via the connecting member 45 and the second lever 46, and the arm shaft 2 repeatedly performs linear motion.

At this time, pins 68,
The force in the axial direction and the force in the direction perpendicular to the axis act via 69, but the former is a holding member 71 that sandwiches the pins 68 and 69,
Due to 71 ′, the latter is received by the bush 63 supporting the turret 3 ′, so that these forces do not act on the arm shaft 2 and a good operation is guaranteed.

As described above, in the present invention, since all the forces acting on the turret 3 'can be received by the holding members 71, 71' and the bush 63, the conventionally provided tapered roller bearing for supporting the turret is unnecessary. become,
The device can be downsized.

The holding members 71 and 71 'are formed in a horseshoe shape with the roller gear cam 31 side opened so as to prevent interference with the cam mechanism and to pinch all roller gears not engaged with the cam mechanism, thereby enabling the turret to move in the axial direction. Movement can be reliably regulated. In addition, since the holding members 71 and 71 'are simply fixed to the inner wall of the housing with bolts from the axial direction of the arm, replacement work when the holding members 71 and 71' are worn out is easy, and the cost and cost required for maintenance can be greatly reduced. it can.

In addition to the small thickness of the bush 63, the bush 63 and the boss 64 are only partially tapered at the lower end of the boss 64 on the roller gear cam 31. , The roller gear cam 31 and the like do not interfere with each other. As a result, the support portion of the turret 3 'and the roller gear engagement portion can be brought close to each other, and the overall length of the turret 3' can be reduced. Further, the closer the turret support portion and the roller gear engagement portion are, the smaller the force in the bending direction acting on the turret 3 ', so that the thickness of the turret 3' can be reduced.

Since the roller gear 4 is composed of the pins 68 and 69, the width of the cam groove formed on the outer periphery of the roller gear cam 31 with which the roller gear 4 is engaged can be reduced, so that the roller gear cam 31 can be downsized. . If the rotating portion can be reduced in size in this way, it is effective not only for reducing the size of the entire device, but also for increasing the speed and response of the device.

A groove 6 formed on the outer periphery of the arm shaft 2
1 has a rectangular cross section with a constant groove width in the depth direction,
It can be processed with ordinary cutting tools. Turret 3 '
Since it is not necessary to form a groove on the inner periphery, the machining of the arm shaft 2 and the turret 3 'becomes easy, and the yield is improved.

[Brief description of the drawings]

FIG. 1 is a front sectional view of a cam type automatic tool changer according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a front sectional view of a conventional cam type automatic tool changer.

FIG. 4 is a sectional view taken along line BB of FIG.

[Explanation of symbols]

 Reference Signs List 1 housing 2 arm shaft 3 'turret 4 roller gear 30 first cam mechanism 40 second cam mechanism 50 electric motor 61 groove 63 bush 68, 69 pin 71, 71' clamping member 72 bolt

Claims (4)

[Claims] 1. A turret in which an arm shaft rotatably supported about an axis and slidable in an axial direction within a housing, a turret in which the arm shaft is slidable in an axial direction and relatively non-rotatable, and a turret. A plurality of roller gears provided on the outer periphery,
A first cam mechanism that engages with the roller gear to perform intermittent rotational movement on the turret and the arm shaft, a second cam mechanism that engages with the arm shaft to perform linear movement repeatedly, and a drive mechanism for driving these cam mechanisms. In a cam type automatic tool changer comprising an electric motor, a roller gear that is not engaged with the first cam mechanism among the plurality of roller gears is sandwiched from both axial sides of an arm shaft,
A cam type automatic comprising: a pair of holding members for restricting axial movement of the turret by taking a supporting reaction force on a housing; and a bush for rotatably supporting a part of the turret on the housing. Tool changer. 2. The holding member according to claim 1, wherein the holding member is a horseshoe-shaped member partially open, and is exchangeably fixed to an inner wall of the housing with a bolt from an axial direction of an arm axis.
The described automatic cam tool changer. 3. The roller gear according to claim 1, wherein the roller gear is constituted by a plurality of pins rotatably supported by holes provided on the outer periphery of the turret and protruding outside the turret by a predetermined length. 3. The cam-type automatic tool changer according to 2. 4. Some of the plurality of pins also protrude inside the turret, and the pins protruding inside the turret are engaged with a plurality of axially extending grooves formed in the outer periphery of the arm shaft and having a rectangular cross section. The turret and the arm shaft are configured so as not to rotate relative to each other.
A cam type automatic tool changer according to any one of the above.