JP2022177871A - Chuck device - Google Patents

Abstract

To provide a chuck device that can hold work-piece in which a whole length reference thereof is set at a front side, while surely pressing the work-piece against back faces of a plurality of claw members.SOLUTION: A chuck device is equipped with: a chuck main body 2; a plurality of claw members 4 provided in the chuck main body 2; a chucking cylinder 6 for opening and closing the plurality of claw members 4; a moving/transmitting mechanism 8 for transmitting output of the chucking cylinder 6 to the plurality of claw members 4; and a pusher 22 that pushes out work-piece to a front side. The chucking cylinder 6 comprises first and second pistons 34 and 36 stored in the cylinder main body 32. The first piston 34 defines a first cylinder chamber 61, the second piston 36 defines a second cylinder chamber 62, an intermediate cylinder chamber 63 is defined between the first and the second pistons 34 and 36, first pressure fluid is supplied to the first cylinder chamber 61 and the intermediate cylinder chamber 63, and second pressure fluid is supplied to the second cylinder chamber 62.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a chuck device capable of stably positioning and holding a workpiece when the front side of the workpiece is the reference for the entire length of the workpiece.

In an NC lathe as an example of a machine tool, a workpiece is detachably held by a chuck device rotated in a predetermined direction by a spindle, and the workpiece held by the chuck device is cut by a cutting tool, for example. (See Patent Document 1, for example). In machining using such an NC lathe, there is a case where the workpiece is attached to a chuck device so that the full length reference of the workpiece is on the front side, and cutting is performed. In such a case, for example, machining is performed as shown in FIG. Installation of things takes place.

In FIG. 10, a conventional chuck device applied to an NC lathe includes a chuck body 102 on which a plurality of (for example, three) claw members 104 move radially at intervals in the circumferential direction. freely worn. The chuck body 102 is also provided with a central hole 106 in which a pusher 108 is mounted. The pushing tool 108 includes a housing body 110 attached to the chuck body 102, an elastic member 112 housed in the housing body 110, such as a coil spring (for example, an air cylinder may be used), and a workpiece. and a pushing member 114 for acting on P to push it forward.

A chucking cylinder 116 (for example, a hydraulic cylinder mechanism) is provided for opening and closing the plurality of claw members 104 . The chucking cylinder 116 has a cylinder body 118, a piston 120 is built in the cylinder body 118, and an output portion 122 of the chucking cylinder 116 is driven and transmitted to the plurality of claw members 104 via a movement transmission mechanism 124. there is With this configuration, when pressure fluid is supplied to the first cylinder chamber 126 of the chucking cylinder 116, the piston 120 moves leftward in FIG. 104 are moved radially inward, thereby holding the workpiece P between the plurality of pawl members 104 . Further, when pressure fluid is supplied to the second cylinder chamber 128 of the chucking cylinder 116, the piston 120 moves rightward in FIG. As a result, the holding of the workpiece P by the plurality of claw members 104 is released.

The workpiece P may be processed into a shape having, for example, a cylindrical body portion 130 and an annular flange portion 132, and the full length reference of the workpiece during this processing is the front side, that is, the front surface of the annular flange portion 132. In some cases, processing is performed with 134 serving as a reference plane. In the case of such processing, the workpiece P is held by the plurality of claw members 104 so that the front surface 134 of the annular flange portion 132 contacts the rear surface 136 of the plurality of claw members 104, and the workpiece P is processed in such a held state. A cutting process for the object P is performed.

JP 2014-176951 A

However, in the conventional chuck device, since the workpiece P is held in the following manner, there is a problem that the workpiece P cannot be held accurately and reliably. That is, conventionally, pressurized fluid is supplied to the second cylinder chamber 128 of the chucking cylinder 116 to move the plurality of claw members 104 in the opening direction (that is, radially outward) to open them, and then , the annular flange portion 132 of the workpiece P is inserted inside the plurality of claw members 104, and then pressure fluid is supplied to the first cylinder chamber 126 of the chucking cylinder 116 to move the plurality of claw members 104 in the closing direction ( That is, it is moved radially inward) to be closed, and in this way the workpiece P is once held by the plurality of claw members 104 .

After that, the pressure fluid is supplied to the second cylinder chamber 128 of the chucking cylinder 116, and then the pressure fluid is supplied to the first cylinder chamber 126 of the chucking cylinder 116. By switching the supply of the pressure fluid in this manner, the plurality of claw members are operated. 104 was closed after being opened. When this temporary opening is made, the elastic restoring action of the elastic member 112 (coil spring) of the pusher 108 is used to push the workpiece P forward through the pushing member 114, thereby pushing the workpiece P forward. The front surface 134 of the annular flange portion 132 is pressed against the rear surface 136 of the plurality of claw members 104, and the workpiece P is held by the plurality of claw members 104 in this contact state.

Conventionally, since the workpiece P is held in this way, for example, when hydraulic oil is used as the pressure fluid, the viscosity of the hydraulic oil changes due to changes in temperature, and as a result, the opening and closing speed of the plurality of claw members 104 increases. Instead, the plurality of claw members 104 hold the workpiece P before it is correctly pushed out by the pushing tool 108. In such a case, there arises a problem that the dimension of the workpiece P after machining varies. Alternatively, the plurality of claw members 104 are opened too much and the workpiece P is separated from the plurality of claw members 104. In such a case, the workpiece P cannot be machined, resulting in a processing error. was doing

SUMMARY OF THE INVENTION An object of the present invention is to provide a chuck device capable of holding a workpiece whose full length reference is on the front side in a state in which the workpiece is reliably pressed against the rear surface of a plurality of claw members.

A chuck device according to claim 1 of the present invention comprises a chuck body that rotates integrally with a main shaft of a machine tool in a predetermined direction, and a plurality of claws that are circumferentially spaced from the chuck body. a member, a chucking cylinder for radially reciprocating the plurality of claw members to hold a workpiece, and a movement transmission for transmitting movement of an output portion of the chucking cylinder to the plurality of claw members. A chuck device comprising a mechanism and a pushing tool attached to the chuck body for pushing the workpiece forward,
The chucking cylinder includes a cylinder body, and first and second pistons housed in the cylinder body. A first cylinder chamber is defined between the cylinder body and the first piston. A second cylinder chamber is defined between and the second piston, an intermediate cylinder chamber is defined between the first and second pistons, and a first protruding shaft portion of the first piston protruding from the cylinder body functions as the output portion of the chucking cylinder, a contact member is attached to a second protruding shaft portion of the second piston protruding from the cylinder body, and a first A first pressure fluid having a pressure is supplied, and a second pressure fluid having a second pressure higher than the first pressure is supplied to the second cylinder chamber. do.

Further, in the chucking device according to claim 2 of the present invention, a first pressure fluid supply means for supplying the first pressure fluid and a means for supplying the second pressure fluid are associated with the chucking cylinder. is provided, and when the plurality of claw members are moved outward in the radial direction to be opened, the first pressure fluid from the first pressure fluid supply means is supplied to the chucking cylinder. When the first pressure fluid from the first pressure fluid supply means is supplied to the intermediate cylinder chamber and the plurality of claw members are moved radially inward to be half-opened, the first pressure fluid from the first pressure fluid supply means is supplied to the chucking cylinder. The second pressure fluid from the second pressure fluid supply means is supplied to the second cylinder chamber of the chucking cylinder, and the plurality of claw members are fed to the first cylinder chamber. The first pressure fluid from the first pressure fluid supply means is supplied to the first cylinder chamber of the chucking cylinder when the chuck is moved inward to hold the workpiece. .

Further, in the chuck device according to claim 3 of the present invention, the contact member comprises an adjusting nut screwed onto the second protruding shaft of the second piston, and the screwing position of the adjusting nut is adjusted to A stroke of the second piston toward the first piston is adjusted by changing the stroke.

Further, in the chuck device according to claim 4 of the present invention, a first flow path switching valve is arranged between the first pressure fluid supply means and the first cylinder chamber and the intermediate cylinder chamber of the chucking cylinder. provided, when the first flow path switching valve is in the first switching position, the first pressure fluid supply means is communicated with the first cylinder chamber and the intermediate cylinder chamber is communicated with the return flow path, When the first flow path switching valve is in the second switching position, the first pressure fluid supply means communicates with the intermediate cylinder chamber, and the first cylinder chamber communicates with the return flow path. Characterized by

Further, in the chuck device according to claim 5 of the present invention, a second flow switching valve is arranged between the second pressure fluid supply means and the second cylinder chamber of the chucking cylinder, When the second flow switching valve is in the first switching position, the second pressure fluid supply means is communicated with the second cylinder chamber, and when the second flow switching valve is in the second switching position, the second pressure fluid supply means is in communication. It is characterized in that the cylinder chamber communicates with the return flow path.

According to the chuck device of claim 1 of the present invention, a chucking cylinder for opening and closing a plurality of claw members includes a cylinder body and first and second pistons accommodated in the cylinder body, A first cylinder chamber is defined between the body and the first piston, a second cylinder chamber is defined between the cylinder body and the second piston, and an intermediate cylinder chamber is defined between the first and second pistons. A first protruding shaft portion of the first piston protruding from the cylinder body functions as an output portion, and a contact member is attached to a second protruding shaft portion of the second piston protruding from the cylinder body. A first pressure fluid having a first pressure is supplied to the first cylinder chamber and the intermediate cylinder chamber, and a second pressure fluid having a second pressure is supplied to the second cylinder chamber. It can be in a half-open and closed position to hold a workpiece firmly against the back of the plurality of claw members.

Further, according to the chucking device of claim 2 of the present invention, the first pressure fluid from the first pressure fluid supply means is supplied to the intermediate cylinder chamber of the chucking cylinder, whereby the plurality of claw members are radially moved. directionally outwardly to an open state, a workpiece can be inserted inside the plurality of claw members, and a first pressure fluid from a first pressure fluid supply means is applied to the first cylinder chamber of the chucking cylinder. and supplying the second pressure fluid from the second pressure fluid supply means to the second cylinder chamber of the chucking cylinder, thereby moving the plurality of claw members radially inward to a half-open state, The front side of the workpiece can be pressed against the back sides of the plurality of claw members, and the first pressure fluid from the first pressure fluid supply means is supplied to the first cylinder chamber of the chucking cylinder, A plurality of pawl members can be moved radially inwardly into a closed position to retain a workpiece.

Further, according to the chuck device of claim 3 of the present invention, the abutment member is composed of the adjusting nut screwed onto the second protruding shaft portion of the second piston. By changing the position, the amount of movement of the second piston can be adjusted, thereby adjusting the half-open position of the plurality of pawl members.

Further, according to the chucking device according to claim 4 of the present invention, the first flow path switching valve is arranged between the first pressure fluid supply means and the first cylinder chamber and the intermediate cylinder chamber of the chucking cylinder. Therefore, by switching the first flow switching valve, the supply of the first pressure fluid to be supplied to the first and intermediate cylinder chambers of the chucking cylinder is switched to control the movement of the first piston. can be done.

Furthermore, according to the chuck device of claim 5 of the present invention, the second flow switching valve is arranged between the second pressure fluid supply means and the second cylinder chamber of the chucking cylinder. The movement of the second piston can be controlled by switching the second flow switching valve.

BRIEF DESCRIPTION OF THE DRAWINGS Sectional drawing which shows the principal part of one Embodiment of the chuck apparatus according to this invention. FIG. 2 is a fluid pressure circuit diagram showing a fluid pressure circuit for controlling pressure fluid supplied to a chucking cylinder of the chuck device of FIG. 1; The figure which shows the state when several claw members of the chuck apparatus of FIG. 1 are made into the open state. 4 is a fluid pressure circuit diagram showing the flow of pressure fluid when opening a plurality of pawl members; FIG. The figure which shows the state when several nail|claw members of the chuck apparatus of FIG. 1 are made into the half-open state. 4 is a fluid pressure circuit diagram showing the flow of pressure fluid when a plurality of pawl members are in a half-open state; FIG. The figure which shows the state which made the front side of a workpiece contact|abut the back side of several nail|claw member. The figure which shows the state when several nail|claw members of the chuck apparatus of FIG. 1 are closed. 4 is a fluid pressure circuit diagram showing the flow of pressure fluid when closing a plurality of pawl members; FIG. Sectional drawing which shows simply the conventional chuck apparatus.

An embodiment of a chuck device according to the present invention will be described below with reference to the accompanying drawings. First, referring to FIG. 1, the structure of one embodiment of the chuck device will be described. a plurality of (for example, three or four) claw members 4 disposed in the space, a chucking cylinder 6 for opening and closing the claw members 4 by radially moving them, and movement of the chucking cylinder 6 and a movement transmission mechanism 8 for transmitting to the plurality of pawl members 4 .

This chuck device is applied to, for example, an NC lathe as an example of a machine tool. is rotated in a predetermined direction. A plurality of claw members 4 are arranged on the front surface of the chuck body 2 and are reciprocated in the radial direction as will be described later. When the plurality of claw members 4 move radially outward and open (see FIG. 3), a workpiece P (for example, see FIG. 3) can be attached to and removed from these claw members 4. . Further, when the plurality of claw members 4 move radially inward and are in a half-open state (see FIGS. 5 and 7), the workpiece P is moved in the axial direction and the front side of the plurality of claw members 4 is moved. It can be brought into contact with the back side. Further, when the plurality of claw members 4 are moved radially inward and closed (see FIG. 8), the workpiece P can be held between the plurality of claw members 4 .

In this embodiment, for example, as shown in FIG. 3, the workpiece P has a shape similar to that shown in FIG. The annular flange portion 12 extends radially outwardly from the outer peripheral surface of the body portion 10 . This workpiece P is processed so that the reference in the axial direction (horizontal direction in FIG. 3) is the front side (specifically, the annular front surface 14 of the annular flange portion 12). , during processing, the front surface 14 of the annular flange portion 12 is brought into contact with the back surfaces of the plurality of claw members 4 as will be described later.

In this embodiment, a notch recess 16 extending radially from the tip is provided on the back surface side of the tip of each claw member 4 , and the front surface 14 of the workpiece P faces the back surface 18 of the notch recess 16 of each claw member 4 . In this contact state, the workpiece P is clamped and held between the plurality of claw members 4 .

The chuck body 2 is further provided with a central hole 20 at its center, and a pusher 22 is attached to this central hole 20 . The push-out tool 22 includes a housing body 24 attached to the chuck body 2, a push-out member 28 mounted in a housing recess 26 of the housing main body 24, and an elastic member interposed between the housing main body 24 and the push-out member 28. The elastic member 30 is composed of, for example, a coil spring, and acts to push the pushing member 28 forward (to the right in FIG. 1).

The chucking cylinder 6 arranged in association with the plurality of claw members 4 includes a cylinder body 32, in which a first piston 34 and a second piston 36 are axially (left and right in FIG. 1). is arranged so as to be able to move back and forth freely. The illustrated first piston 34 includes a first piston body 38 that moves along the inner peripheral surface of the cylinder body 32, first boss portions 40 and 42 provided on both sides of the first piston body 38, and first first shaft portions 44, 46 extending axially from the boss portions 40, 42, one first shaft portion 44 extending outwardly through one end wall 48 of the cylinder body 32; The first shaft portion 44 (constituting the first projecting shaft portion) functions as an output portion of the chucking cylinder 6 . Incidentally, such a chucking cylinder 6 can be composed of a fluid pressure cylinder mechanism using fluid pressure. can be done.

The second piston 36 includes a second piston body 50 that moves along the inner peripheral surface of the cylinder body 32, second boss portions 52 and 54 provided on both sides of the second piston body 50, and a second piston body 50. a second shank 56 extending axially from the boss 54, the second shank 56 extending outwardly through the other end wall 58 of the cylinder body 32; A contact member 59 is attached to (constituting the second projecting shaft portion).

In this embodiment, the contact member 59 is composed of an adjusting nut, which is screwed onto the second shaft portion 56 . With this configuration, the stroke of the second piston 36 can be adjusted by changing the screwing position of the adjustment nut. The stroke of the piston 36 can be adjusted to be smaller (or larger).

In this embodiment, a through support hole 60 is provided axially through the second piston 36 (specifically, the second piston body 50, the second boss portions 52 and 54, and the second shaft portion 56), The other first shaft portion 46 of the first piston 34 is movably supported in the through support hole 60, and thus configured, the first and second pistons 34, 36 are mutually They are arranged relatively movably.

In this chucking cylinder 6, as shown in FIG. 1, a first cylinder chamber 61 is defined between the cylinder body 32 (specifically, one end wall 48) and the first piston 34. A second cylinder chamber 62 is defined between 32 (specifically, the other end wall 58) and the second piston 36, and an intermediate cylinder chamber 63 is defined between the first piston 34 and the second piston 36. stipulated. In relation to this, one end of the cylinder body 32 is provided with a first fluid communication hole 64 that communicates with the first cylinder chamber 61 , and the other end thereof communicates with the second cylinder chamber 62 . A second fluid communication hole 65 is provided, and an intermediate communication hole 66 communicating with the intermediate cylinder chamber 63 is provided at the intermediate portion thereof.

In this embodiment, the movement transmission mechanism 8 for transmitting the movement of the chucking cylinder 6 to the plurality of claw members 4 further includes a transmission rod 67 and a swing transmission member 68. As shown in FIG. A sleeve member 69 is screwed to one end of the transmission rod 67 . A male threaded shaft portion 70 is provided at the other end of the transmission rod 67, and the male threaded shaft portion 70 is screwed to a female threaded portion of the first shaft portion 44 (first projecting shaft portion) of the first piston 34. there is With this configuration, when the transmission rod 67 moves in the direction indicated by the arrow 71, the plurality of pawl members 4 move radially outward (that is, , opening direction).

The chucking cylinder 6 is operated and controlled by a fluid pressure control circuit shown in FIG. The illustrated fluid pressure control circuit includes first pressure fluid supply means for supplying pressure fluid (first pressure fluid) at a first pressure (for example, about 0.5 to 3.0 MPa), and a second pressure fluid supply means for supplying pressure fluid (second pressure fluid) at a large second pressure (for example, about 1.0 to 3.4 MPa), and in this embodiment, a supply for supplying pressure fluid A pressure reducing valve 75 disposed in a first branch supply line 74 branching from the line 73 functions as a first pressure fluid supply means for supplying a first pressure fluid (e.g., pressure oil) at a first pressure, A pressure regulating valve 88 disposed in a second branch supply line 76 branching from the supply line 73 serves as a second pressure fluid supply means for supplying a second pressure fluid (for example, pressure oil) at a second pressure. Function.

The pressure fluid (first pressure fluid) supplied through the first branch supply line 74 is configured to be supplied to the first cylinder chamber 61 and the intermediate cylinder chamber 63 of the chucking cylinder 6 . In this form, a first flow switching valve 77 is provided in relation to the pressure reducing valve 75, and the first branch supply line 74 and the first branch return line 78 are connected to the inflow side of the first flow switching valve 77. In addition, a first fluid line 79 communicating with the first cylinder chamber 61 and an intermediate fluid line 80 communicating with the intermediate cylinder chamber 63 are connected to the cylinder side of the first flow path switching valve 77 . A check valve 81 is arranged between the pressure reducing valve 75 and the first flow path switching valve 77 .

With this configuration, when the first flow path switching valve 77 is positioned at the first switching position shown in FIG. 2 (and FIG. 4), the first branch supply line 74 and the intermediate fluid line 80 are connected. At the same time, the first branch return line 78 and the first fluid line 79 are connected, and the pressure fluid from the first branch supply line 74 is supplied to the intermediate cylinder chamber 63 of the chucking cylinder 6 through the intermediate fluid line 80, Also, the pressure fluid in the first cylinder chamber 61 of the chucking cylinder 6 is returned to the return line 82 through the first fluid line 79 and the first branch return line 78 . When the first flow path switching valve 77 is positioned at the second switching position shown in FIG. 6 (and FIG. 9), the first branch supply line 74 and the first fluid line 79 are connected, and the first A branch return line 78 and an intermediate fluid line 80 are connected, and the pressure fluid from the first branch supply line 74 is supplied through the first fluid line 79 to the first cylinder chamber 61 of the chucking cylinder 6, and the chucking cylinder 6 is returned to return line 82 through intermediate fluid line 80 and first branch return line 78 .

The pressure fluid (second pressure fluid) supplied through the second branch supply line 76 is configured to be supplied to the second cylinder chamber 62 of the chucking cylinder 6 . In this embodiment, a second flow switching valve 83 is provided in relation to the pressure regulating valve 76, and the second branched supply line 76 and the second branched return line 84 are connected to the inflow side of the second flow switching valve 83. A second fluid line 85 communicating with the second cylinder chamber 62 is connected to the cylinder side of the second flow path switching valve 83 .

With this configuration, when the second flow path switching valve 83 is positioned at the first switching position shown in FIG. 2 (and FIG. 6), the second branch supply line 74 and the second fluid line 85 are connected. The pressure fluid (second pressure fluid) from the second branch supply line 76 is supplied to the second cylinder chamber 62 of the chucking cylinder 6 through the second fluid line 85 . 4 (and FIG. 9), the second branch return line 84 and the second fluid line 85 are connected, and the chucking cylinder 6 is returned to the return line 82 through the second fluid line 85 and the second branch return line 84 .

Next, referring mainly to FIGS. 3 to 9, the chucking operation of the workpiece P by the chucking device described above will be described. In order to hold the workpiece P in the chuck device with the front side in the axial direction as a reference, first, the plurality of claw members 4 are opened as shown in FIGS. 3 and 4 . The first flow path switching valve 77 is positioned at the first switching position, and the second flow path switching valve 83 is positioned at the second switching position. In this switching state, the pressure fluid from the supply line 73 is supplied to the intermediate cylinder chamber 63 of the chucking cylinder 6 through the first branch supply line 74 and the intermediate fluid line 80, The pressure fluid in the cylinder chamber 61 is returned to the return line 82 through the first fluid line 79 and the first branch return line 78, and the pressure fluid in the second cylinder chamber 62 of the chucking cylinder 6 is returned to the second fluid line 85 and the first branch return line 78. It is returned to return line 82 through second branch return line 84 .

When the pressure fluid is supplied to the intermediate cylinder chamber 63 in this manner, the first piston 34 is moved to the right in FIG. The second piston 36 is moved to the left in FIG. 3 (to a position where its second boss portion 54 abuts against the other end wall 58), and this The movement of the first piston 34 extends the first shaft portion 44 (first projecting shaft portion).

Thus, the movement of the first shaft portion 44 is transmitted to the plurality of pawl members 4 via the movement transmission mechanism 8 (transmission rod 68, swing transmission member 68, etc.) (see FIG. 2), and these pawl members 4 are shown by arrows. , to be in an open state (that is, a state in which the annular flange portion 12 of the workpiece P can be inserted inside through the plurality of claw members 4).

When the plurality of claw members 4 are opened, as can be understood from FIGS. 3 and 5, a workpiece P transported and held by a loader device (not shown) is inserted inside through between the claw members 4. , until the annular flange portion 12 contacts the front surface of the chuck body 2 . When inserted in this manner, the inserted workpiece P acts on the pushing member 28 of the pushing tool 22, causing the elastic member 30 to contract.

After inserting the workpiece P in this manner, the plurality of claw members 4 are brought into a half-open state as shown in FIGS. The first switching valve 77 is switched from the first switching position to the second switching position, and the second switching valve 83 is switched from the second switching position to the first switching position. In this switching state, the pressure fluid from the supply line 73 is supplied to the first cylinder chamber 61 of the chucking cylinder 6 through the first branch supply line 74 and the first fluid line 79, The pressure fluid in the intermediate cylinder chamber 63 is returned to the return line 82 through the intermediate fluid line 80 and the first branch return line 78, and the pressure fluid from the supply line 73 is returned through the second branch supply line 76 and the second fluid line 85. It is fed to the second cylinder chamber 62 of the chucking cylinder 6 .

When the pressure fluid is supplied to the first cylinder chamber 61 and the second cylinder chamber 62 in this manner, the first piston 34 is moved to the left in FIG. 3 as indicated by the arrows in FIG. Piston 36 is moved to the right in FIG. At this time, since the pressure of the pressure fluid (second pressure fluid) supplied to the second cylinder chamber 62 is higher than the pressure of the pressure fluid (first pressure fluid) supplied to the first cylinder chamber 61, The second piston 36 is preferentially moved, and the contact member 59 attached to the second shaft portion 56 (second projecting shaft portion) of the second piston 36 contacts the other end wall 58 of the cylinder body 32. The first piston 34 is moved to the position indicated by the arrow until the first boss 42 contacts the second boss portion 52 of the second piston 36, and the first piston 34 is moved to the position indicated by the arrow. movement causes the first shaft portion 44 (first projecting shaft portion) to contract.

Thus, the contraction motion of the first shaft portion 44 is transmitted to the plurality of claw members 4 via the movement transmission mechanism 8 (transmission rod 68, swing transmission member 68, etc.) (see FIG. 2). moves radially inward as indicated by an arrow to be in a half-opened state (that is, a state in which the annular flange portion 12 of the workpiece P can abut against the rear surface 18 of the notch recess 16 of the plurality of claw members 4). .

After that, in the half-opened state of these claw members 4, when the workpiece P is released from being conveyed and held by the loader device (not shown), as shown in FIG. The object P is pushed forward in the axial direction (to the right in FIG. 7), the front surface 14 of the annular flange portion 12 of the object P abuts against the back surfaces 18 of the plurality of claw members 4, and the object P is pushed forward in the axial direction. is positioned as a reference. At this time, since the plurality of claw members 4 are held in a half-open state, the plurality of claw members 4 do not pinch the work piece P during this extrusion, and the work piece P is held between the plurality of claw members 4. The front surface 14 of the annular flange portion 12 of the workpiece P can be reliably brought into contact with the back surfaces 18 of the plurality of claw members 4 without being dislodged outward from the gap.

After that, as shown in FIGS. 8 and 9, the plurality of claw members 4 are closed. While the first flow path switching valve 77 is held at the second switching position, the second flow path switching valve 83 is switched from the first switching position to the second switching position. In this switching state, the pressure fluid from the supply line 73 is supplied to the first cylinder chamber 61 of the chucking cylinder 6 through the first branch supply line 74 and the first fluid line 79, The pressure fluid in the intermediate cylinder chamber 63 is returned to the return line 82 through the intermediate fluid line 80 and the first branch return line 78, and the pressure fluid in the second cylinder chamber 62 of the chucking cylinder 6 is returned to the second fluid line 85 and the first branch return line 78. It is returned to return line 82 through second branch return line 84 .

When the pressure fluid (first pressure fluid) is supplied to the first cylinder chamber 61 in this manner, the first piston 34 is moved leftward in FIG. 3 as indicated by the arrow in FIG. The piston 36 is also moved leftward in FIG. 3, the first piston 34 is moved in the direction indicated by the arrow until the first boss portion 42 contacts the second boss portion 52 of the second piston 36, and the second piston 36 is moved in the direction indicated by the arrow until the second boss portion 54 abuts against the other end wall 58 of the cylinder body 32 . (the first protruding shaft portion) further contracts.

Thus, the contraction motion of the first shaft portion 44 is transmitted to the plurality of claw members 4 via the movement transmission mechanism 8 (transmission rod 68, swing transmission member 68, etc.) (see FIG. 2), and these claw members 4 moves further inward in the radial direction as indicated by the arrows to be in a closed state. The workpiece P can be held in the chuck device so that the is on the front side.

Although one embodiment of the chucking device according to the present invention has been described above, the present invention is not limited to such an embodiment, and various changes and modifications can be made without departing from the scope of the present invention.

For example, in the above-described embodiment, contraction (or expansion) of the output portion of the chucking cylinder 6 moves the plurality of claw members 4 radially inward to the closed state (or radially outward). to the open state), on the contrary, contraction (or expansion) of the output portion of the chucking cylinder 6 causes the plurality of claw members 4 to move radially outward. to the open state (or move radially inward to the closed state).

Further, for example, in the above-described embodiment, the pressure fluid flowing through the supply line 73 is set to the second pressure, and the pressure fluid (second pressure fluid) flowing through the supply line 73 is supplied to the second cylinder chamber 62 of the chucking cylinder 6. At the same time, the pressure fluid (first pressure fluid) decompressed from the second pressure to the first pressure is supplied to the first cylinder chamber 61 and the intermediate cylinder chamber 63 of the chucking cylinder 6. Not limited to such a configuration, for example, the pressure of the pressure fluid supplied through the supply line 73 is set higher than the second pressure, and the pressure fluid (second pressure fluid) decompressed from this high pressure to the second pressure is supplied to the second cylinder chamber 62 of the chucking cylinder 6, and the pressure fluid (first pressure fluid) decompressed from this high pressure to the first pressure is supplied to the first cylinder chamber 61 and the intermediate cylinder chamber of the chucking cylinder 6 63. Alternatively, instead of these configurations, a first pressure fluid supply source (for example, composed of a fluid pressure pump) that supplies pressure fluid of a first pressure (first pressure fluid) and a pressure fluid of a second pressure (second pressure fluid) 2 pressure fluid) is provided, and the pressure fluid from the first pressure fluid supply source (first pressure fluid) is supplied to the chucking cylinder 6 at the first pressure fluid. 1 cylinder chamber 61 and the intermediate cylinder chamber 63, and pressure fluid (second pressure fluid) from the second pressure fluid supply source is supplied to the second cylinder chamber 62 of the chucking cylinder 6. may

2, 102 chuck body 4, 104 claw member 6, 116 chucking cylinder 8, 124 movement transmission mechanism 22 pushing tool 32, 118 cylinder body 34 first piston 36 second piston 44 first shaft portion (first projecting shaft portion)
56 second shaft (second projecting shaft)
58 contact member (adjustment nut)
61, 126 First cylinder chamber 62, 128 Second cylinder chamber 63 Intermediate cylinder chamber 77 First flow switching valve 83 Second flow switching valve P Workpiece

Claims (5)

A chuck body that rotates integrally with a main shaft of a machine tool in a predetermined direction, a plurality of claw members that are arranged at intervals in a circumferential direction of the chuck body, and a plurality of claw members that reciprocate in a radial direction. a chucking cylinder for moving and holding a workpiece; a movement transmission mechanism for transmitting movement of an output portion of the chucking cylinder to the plurality of claw members; In a chuck device comprising a pusher that pushes the forward side,
The chucking cylinder includes a cylinder body, and first and second pistons housed in the cylinder body. A first cylinder chamber is defined between the cylinder body and the first piston. A second cylinder chamber is defined between and the second piston, an intermediate cylinder chamber is defined between the first and second pistons, and a first protruding shaft portion of the first piston protruding from the cylinder body functions as the output portion of the chucking cylinder, a contact member is attached to a second protruding shaft portion of the second piston protruding from the cylinder body, and a first A first pressure fluid having a pressure is supplied, and a second pressure fluid having a second pressure higher than the first pressure is supplied to the second cylinder chamber. chuck device. A first pressure fluid supply means for supplying the first pressure fluid and a second pressure fluid supply means for supplying the second pressure fluid are provided in relation to the chucking cylinder, and the plurality of claws When the members are moved radially outward to be opened, the first pressure fluid from the first pressure fluid supply means is supplied to the intermediate cylinder chamber of the chucking cylinder to move the plurality of claw members. When moving radially inward and half-opening, the first pressure fluid from the first pressure fluid supply means is supplied to the first cylinder chamber of the chucking cylinder, and the second pressure is applied. When the second pressure fluid from the fluid supply means is supplied to the second cylinder chamber of the chucking cylinder and the plurality of claw members are moved radially inward to hold the workpiece, 2. A chucking device according to claim 1, wherein said first pressure fluid from said first pressure fluid supply means is supplied to said first cylinder chamber of said chucking cylinder. The contact member is composed of an adjusting nut screwed onto the second protruding shaft portion of the second piston, and by changing the screwing position of the adjusting nut, the second piston is moved toward the first piston. 3. The chuck device according to claim 1, wherein the amount of movement of is adjusted. A first flow switching valve is disposed between the first pressure fluid supply means and the first cylinder chamber and the intermediate cylinder chamber of the chucking cylinder, and the first flow switching valve is in the first switching position. When the first pressure fluid supply means is in communication with the first cylinder chamber, the intermediate cylinder chamber is in communication with the return flow path, and the first flow path switching valve is in the second switching position, 4. The chuck according to claim 1, wherein said first pressure fluid supply means communicates with said intermediate cylinder chamber, and said first cylinder chamber communicates with said return passage. Device. A second flow switching valve is disposed between the second pressure fluid supply means and the second cylinder chamber of the chucking cylinder, and when the second flow switching valve is in the first switching position, the A second pressure fluid supply means is communicated with the second cylinder chamber, and the second cylinder chamber is communicated with the return flow path when the second flow path switching valve is in the second switching position. The chuck device according to claim 4.

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