JP3814715B2 - Article gripping device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an article gripping device that is provided at the tip of a rotating shaft and grips an article.
[0002]
[Prior art]
For example, in order to mount a workpiece on a machine tool such as a lathe, a chuck device that grips the workpiece on a spindle is provided. Conventionally, as this chuck device, a cylindrical chuck body that is attached to the tip of the main shaft and has a through hole extending in the axial direction in the center portion, and an equiangular interval in the circumferential direction on the workpiece mounting side surface of the chuck body A plurality of gripping members that are linearly moved in the radial direction thereof, an operation rod disposed in the main shaft so as to be movable in the axial direction, and a fluid pressure cylinder that moves the operation rod in the axial direction of the main shaft. In the chuck body, there is known one provided with a transmission means provided between the operating rod and each gripping member and converting the linear movement of the operating rod into the linear movement of the gripping member. In this chuck device, a plurality of grooves that are located on the chuck body and open to the workpiece mounting side surface are formed in the chuck body at equal angular intervals in the circumferential direction of the chuck body. Both ends of the groove in the radial direction are open on the inner peripheral surface of the through hole and the outer peripheral surface of the chuck body. The groove bottom side end portion of the groove is widened, whereby a guide groove portion located on the radius of the chuck body is formed over the entire length of the groove. The gripping member is fixed to a support member that is slidably fitted in the groove, and a guided portion that is slidably engaged with the guide groove portion of the groove is fixedly provided on the support member.
[0003]
[Problems to be solved by the invention]
However, the conventional chuck has the following problems. That is, since the groove and the guide groove portion formed in the chuck body are located on the radius of the chuck body, the length of the guide groove portion is the radial length of the opening to the workpiece mounting side surface of the groove, that is, Since it is equal to the radial distance between the outer peripheral surface of the chuck body and the inner peripheral surface of the through hole, it is relatively short, and the transmission means is arranged in the through hole, so that the support member along the guide groove portion The movement of the guided portion is limited, and as a result, the amount of movement of the gripping member becomes relatively small. Further, as shown in FIG. 7, the center of gravity (G1) of the combination of the gripping member (20) and the support member (21) including the guided portion is located on the radius of the chuck body (22). When the spindle rotates at a high speed, the centrifugal force acts on the gripping member (20) and the support member (21) as a radially outward force of the chuck body (22), and this centrifugal force causes the gripping member (20 ) May be reduced.
[0004]
The object of the present invention is to solve the above-mentioned problems, and to increase the amount of movement of the gripping member as compared with the conventional case, and to grip the article that can suppress a decrease in gripping force with respect to the article when the rotating shaft rotates. To provide an apparatus.
[0005]
[Means for Solving the Problems and Effects of the Invention]
An article gripping apparatus according to the present invention includes a gripping apparatus body having an article mounting side surface to which an article is mounted and attached to the tip of a rotating shaft, and a circumferential direction about the axis of the rotating shaft on the article mounting side surface of the gripping apparatus body Are provided at equal angular intervals and linearly move in the radial direction of the rotating shaft, an operating rod disposed in the rotating shaft so as to be movable in the axial direction, and an operating rod connected to the rotating shaft. A rod driving means for moving in the axial direction, provided between the operating rod and each gripping member in the gripping device main body, and the movement of the operating rod in the rotational axis direction is changed to the radial movement of the gripping member. an article gripping device and a transmission means for converting, the gripping device main body, is formed with a plurality of grooves which are opening together with the opening to the article attachment side extending in a radial direction of the rotary shaft, the bottom ends of the grooves Center of kicking the width direction, are offset in the circumferential direction with respect to the center in the width direction of the groove opening in the bottom end of the groove, is provided over the entire length of the moving direction parallel to the guide portion is a groove of the bunch support member The gripping member is fixedly provided on a support member that is slidably fitted in the groove, and the support member is provided with a guided portion that is slidably engaged with the guide portion of the groove. Is.
[0006]
According to the article gripping device of the present invention, the gripping device main body is formed with a plurality of grooves that open on the article mounting side surface and the openings extend in the radial direction of the rotation shaft. Since the guide portion that is offset and parallel to the moving direction of the gripping member is provided over the entire length of the groove, the length of the guide portion is longer than that of the conventional device, and as a result, the guide member is fixedly provided on the gripping member. The amount of movement of the guided portion along the guide portion is also relatively large. Therefore, the amount of movement of the gripping member in the radial direction of the rotation axis also increases. Further, the gripping member is fixedly provided on a support member that is slidably fitted in the groove, and a guided portion that is slidably engaged with the guide portion of the groove is fixedly provided on the support member. Therefore, a part of the centrifugal force acting on the gripping member and the support member when the rotation shaft rotates can be received by the guide portion, and a decrease in gripping force by the gripping member on the article can be suppressed.
[0007]
In the article gripping apparatus according to the present invention, the gripping member may have article gripping surfaces at a plurality of positions different with respect to the radial direction of the rotation shaft. In this case, the types of articles that can be held by one type of holding member increase. In addition, since the movement amount of the gripping member in the radial direction of the rotation axis is larger than that in the conventional apparatus, the gripping member has an article gripping surface at a plurality of different positions in the radial direction of the rotation axis in the conventional apparatus. Compared with the case where it is doing, the dimension range of the article | item which can be hold | gripped becomes large. That is, in the conventional apparatus, for example, the gripping member has two gripping surfaces at an interval of 20 mm, the amount of movement of the gripping member in the radial direction of the rotating shaft is 20 mm, and the gripping member moves to the inner end in the radial direction of the rotating shaft. If it is possible to grip an article having a diameter of 20 mm, it is theoretically possible to grip an article having a diameter of 20 to 60 mm with the gripping surface on the inner side in the radial direction of the rotation axis. An article having a diameter of 60 to 100 mm can be gripped, and an article having a diameter of 20 to 100 mm can be handled. On the other hand, in the apparatus of the present invention, for example, the gripping member has two gripping surfaces at an interval of 30 mm, the amount of movement of the gripping member in the radial direction of the rotating shaft is 30 mm, and the gripping member is in the radial direction of the rotating shaft. If it is possible to grip an article having a diameter of 20 mm when moved to the inner end, it is theoretically possible to grip an article having a diameter of 20 to 80 mm on the gripping surface on the inner side in the radial direction of the rotation axis. An article having a diameter of 80 to 140 mm can be grasped by the grasping surface, and an article having a diameter of 20 to 140 mm can be handled.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. In this embodiment, the article gripping device according to the present invention is applied to a chuck device that is provided on a spindle of a lathe and grips a workpiece.
[0009]
In the following description, the lower side of FIG. 1 is the front and the opposite side is the rear.
[0010]
1 to 3, the chuck device is a cylindrical chuck body (3) having a through hole (2) attached to the front end of a hollow main shaft (1) (rotating shaft) and extending in the axial direction at the center. (Grip device body) and a plurality of top jaws that are provided at equal angular intervals in the circumferential direction on the workpiece mounting side surface (3a) (article mounting side surface) of the chuck body (3) and linearly move in the radial direction ( 4) (gripping member), operating rod (5) arranged to move in the axial direction in the main shaft (1), and operating rod (5) arranged on the rear end side of the main shaft (1) Is provided between the operating rod (5) and each top jaw (4) in the chuck body (3) and a fluid pressure cylinder (not shown) that moves the main shaft (1) in the axial direction. Transmission means for converting the movement in the axial direction of 5) into the linear movement of the top jaw (4).
[0011]
The chuck body (3) has a plurality of, here three support grooves (6), which open in the workpiece mounting side surface (3a) and extend in the radial direction of the chuck body (3) in the circumferential direction. Are formed at equiangular intervals. Each support groove (6) is inclined with respect to a plane including the central axis of the chuck body (3) and passing through the center in the width direction of the opening (6a) from the opening (6a) side toward the groove bottom side. ing. The inclination directions in all the support grooves (6) are the same. Note that both the inner and outer ends of each support groove (6) in the radial direction are opened to the inner peripheral surface of the through hole (2) and the outer peripheral surface of the chuck body (3), respectively. By widening the groove bottom end of the support groove (6), the guide groove (7) (guide) is offset from the opening (6a) of the support groove (6) and parallel to the moving direction of the top jaw (4). Part) is provided over the entire length of the support groove (6). As is clear from FIG. 2, the length L of the opening (6a) of the support groove (6) is the radial distance between the outer peripheral surface of the chuck body (3) and the inner peripheral surface of the through hole (2). However, the length L1 of the guide groove (7) is longer than this.
[0012]
The chuck body (3) is formed with a plurality of slots (8) extending from the rear end surface to the guide groove portions (7) of the support grooves (6). Each slot (8) is offset from the opening (6a) of the support groove (6) and is parallel to the opening (6a). Each slot (8) is open to the inner peripheral surface of the through hole (2) over its entire length. A plurality of bottomed holes (9) are formed in the chuck body (3) from appropriate locations on the outer peripheral surface in a direction perpendicular to each slot (8) and the tip of the chuck body (3) extends beyond the slot (8). Has been.
[0013]
The top jaw (4) is screwed to a master jaw (11) (support member) that is slidably fitted in each support groove (6). The master jaw (11) is integrally formed with a guided portion (12) that is slidable so as not to drop into the guide groove portion (7) over its entire length. A notch (13) is formed in a portion near one end of the guided portion (12) in the length direction, that is, an end portion on the through hole (2) side. Further, the top jaw (4) has gripping surfaces (4a) and (4b) at a plurality of different positions with respect to the radial direction of the chuck body (3). Each gripping surface (4a) (4b) is provided with a plurality of protrusions.
[0014]
The transmission means is configured as described below. As shown in FIGS. 4 and 5, a slider (14) sliding in the front-rear direction in the through hole (2) of the chuck body (3) is screwed to the front end of the operating rod (5). On the outer peripheral surface of the slider (14), a plurality of sliding contact portions (14a) with respect to the inner peripheral surface of the through hole (2) are provided in the circumferential direction. The front end surface of the slider (14) is integrally formed with a guided portion (14b) that protrudes forward and is slidably inserted into a lid (16) disposed at the front end of the through hole (2). Has been. Further, a plurality of, here three, recesses (15) are formed on the outer peripheral surface of the slider (14) at intervals in the circumferential direction. An L-shaped lever (17) is placed in each slot (8) of the chuck body (3), and both ends of the pin (18) fixed in a penetrating manner at the center of the slot are inserted into the bottomed hole (9). The lever (17) can be swung around the axis of the pin (18) by being rotatably inserted into the pin (18). One end of the lever (17) is formed with a first engaging portion (17a) that fits in the recess (15) of the slider (14) and has an arcuate peripheral surface, and the other end is a master jaw. A second engaging portion (17b) is formed that fits within the notch (13) of (11) and has an arcuate peripheral surface. When the operating rod (5) moves rearward, the slider (14) slides backward in the through hole (2), and the lever (17) is swung clockwise in FIGS. 4 and 5. As a result, the guided portion (12) of the master jaw (11) is guided by the guide groove portion (7), and the master jaw (11) linearly moves in the support groove (6) toward the through hole (2) (FIG. 4). The workpiece is gripped by the top jaw (4). When the operating rod (5) moves forward, the slider (14) slides backward in the through hole (2), and the lever (17) is swung counterclockwise in FIGS. As a result, the guided portion (12) of the master jaw (11) is guided by the guide groove portion (7), and the master jaw (11) moves linearly in the support groove (6) to the side opposite to the through hole (2). (See FIG. 5), and the workpiece is released from the top jaw (4).
[0015]
In the above chuck device, the length L of the opening (6a) of the support groove (6) is a radial distance between the outer peripheral surface of the chuck body (3) and the inner peripheral surface of the through hole (2). Although the length L1 of the guide groove (7) is longer than this, the slider (14) that constitutes the transmission means is disposed in the through hole (2) of the chuck body (3). Even so, compared to the conventional apparatus, the movement of the guided portion (12) of the master jaw (11) is less likely to be restricted, and the movement amount is increased. Accordingly, the amount of movement of the top jaw (4) also increases.
[0016]
Further, as shown in FIG. 6, the position of the center of gravity G of the master jaw (11) and the top jaw (4) is shifted from the radius of the chuck body (3) toward the guide groove (7). Therefore, when the main shaft (1) rotates at a high speed, the lateral component (C1) of the centrifugal force (C) acting on the master jaw (11) and the top jaw (4) is received by the inner surface of the guide groove (7). become. Therefore, the component (C2) which tries to move the master jaw (11) and the top jaw (4) of the centrifugal force (C) to the opposite side to the through hole (2) is different from the case of the conventional device. Compared to this, it is possible to suppress the reduction in gripping force by the top jaw (4) on the workpiece.
[0017]
In the above-described embodiment, the article gripping device according to the present invention is applied to a chuck device for gripping a workpiece of a machine tool. However, the present invention is not limited to this and is also applicable to an article gripping device of other devices. Is possible.
[Brief description of the drawings]
FIG. 1 is a partially cutaway plan view of a chuck device to which an article gripping device according to the present invention is applied.
FIG. 2 is a partially cut away front view.
3A is an exploded perspective view showing a chuck main body, a top jaw, and a master jaw, and FIG. 3B is a perspective view of the master jaw as viewed from a direction different from FIG.
4 is a cross-sectional view taken along line IV-IV in FIG.
FIG. 5 is a view corresponding to FIG. 4 showing a state different from FIG. 4;
FIG. 6 is a diagram schematically showing the positions of the center of gravity of the top jaw and the master jaw and the force acting on them.
FIG. 7 is a diagram schematically showing the positions of the center of gravity of a top jaw and a master jaw and the force acting on them in a conventional chuck device.
[Explanation of symbols]
(1): Main shaft (rotating shaft)
(3): Chuck body (gripping device body)
(3a): Workpiece mounting side (article mounting side)
(4): Top jaw (gripping member)
(4a) (4b): Grasping surface
(5): Operation rod
(6): Support groove
(6a): Opening
(7): Guide groove (guide part)
(11): Master jaw (support member)
(12): Guided part

Claims (2)

A gripping device main body attached to the tip of the rotary shaft and having an article mounting side surface on which an article is mounted; and provided on the article mounting side surface of the gripping device main body at equal angular intervals in the circumferential direction around the axis of the rotary shaft; A plurality of gripping members that linearly move in the radial direction of the rotating shaft, an operating rod disposed in the rotating shaft so as to be movable in the axial direction, and a rod driving means that moves the operating rod in the axial direction of the rotating shaft And a transmission means provided between the operating rod and each gripping member in the gripping device main body and for converting the movement of the operating rod in the rotation axis direction to the movement of the gripping member in the radial direction of the rotation axis. In the article gripping device,
A plurality of grooves are formed in the gripping device main body so as to open on the article mounting side surface and the openings extend in the radial direction of the rotation shaft. The center in the width direction at the bottom end of the groove is the center in the width direction of the groove opening are displaced in the circumferential direction with respect to the bottom end of the groove, is provided over the entire length of the moving direction parallel to the guide portion is a groove of the bunch support member, the gripping member is fitted slidably in a groove support An article gripping device provided with a fixed shape on a member, and a supported portion with a guided portion slidably engaged with a guide portion of a groove.   The article gripping apparatus according to claim 1, wherein the gripping member has article gripping surfaces at a plurality of different positions with respect to the radial direction of the rotation shaft.

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