Sub collet chuck

Abstract

To provide a sub-collet chuck capable of suppressing breakage at a gripping portion in an object to be gripped.SOLUTION: A sub-collet chuck 200 comprises three sub-claw bodies 201 and one clamp base 210 inside a collet chuck 100. The sub-claw body 201 has a gripping part 201a for gripping an object to be gripped WK, and also has a pressure-receiving part 201b facing a claw part 104 of the collet chuck 100. Further, in the sub-claw body 201, claw body through-holes 202 are formed each having a displacement allowance S relative to a through-hole pressing body 205. The through-hole pressing body 205 penetrates through the claw body through-hole 202 and is fastened to the clamp base 210 via a pressing elastic body 206. The clamp base 210 supports the three sub-claw bodies 201.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a sub-collet chuck that is attached to a collet chuck that grips an object to be machined, and that grips the object. [Background technology]

[0002] Collet chucks for gripping objects to be machined have been known for some time. For example, the following Patent Document 1 discloses a collet chuck that grips an object by arranging three aperture members inside a cylindrical body member that expands and contracts in the radial direction. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2000-158216 A

[0004] However, in the collet chuck described in Patent Document 1, the fitting portion formed at the tip of the body member and divided into three pieces tilts radially inward to grip the object to be gripped via the aperture member, so that the inner surface of the aperture member tilting radially inward comes into linear contact with the object to be gripped along the circumferential direction, resulting in a problem that the gripping portion of the object to be gripped may be damaged due to concentration of contact load. Summary of the Invention

[0005] The present invention has been made to address the above-mentioned problems, and an object of the present invention is to provide a sub-collet chuck that can suppress damage to the gripping portion of the object to be gripped.

[0006] In order to achieve the above object, the present invention is characterized in that one end of a cylindrical body has a claw portion divided into at least two in the circumferential direction, and the claw portion is inclined in the radial direction. Collet bodyA sub-collet chuck that is attached to the collet chuck and grips an object to be gripped, the sub-collet chuck comprising at least two sub-jaw bodies that are arranged adjacent to the side of the jaw portion that grips the object to be gripped and grip the object to be gripped; The claws of the collet body are inclined in the radial direction, and the pressure applied to the sub-claws is proportional to the pressure applied to the sub-claws. a clamp base that supports the sub-claw body via a radial slide mechanism for displacing the sub-claw body back and forth in the radial direction of the cylindrical body; The radial slide mechanism includes a claw body through hole penetrating the sub-claw body, a penetrating pressing body penetrating the claw body through hole and attached to the clamp base to press the sub-claw body against the clamp base, and a pressing elastic body between the sub-claw body and the penetrating pressing body for elastically pressing the sub-claw body against the clamp base. having The claw body through hole is formed to have a size that allows the sub-claw body to be displaced relative to the clamp base, and the through-pressing body presses the sub-claw body against the clamp base with a force that allows the sub-claw body to slide. The point is that.

[0007] According to the features of the present invention configured in this manner, the sub-collet chuck has multiple sub-claw bodies that are capable of reciprocating displacement in the radial direction of the collet chuck via a radial slide mechanism on the side of the claw portion of the collet chuck that grips the object to be gripped, so that when the claw portion is tilted, the sub-claw bodies move parallel to the radial direction, allowing the object to be gripped to be gripped by surface contact and reducing damage such as pressure marks on the gripping portion.

[0008] This is how it was configured Features of the invention According to the present invention, the sub-collet chuck presses the sub-claw body against the clamp base with a sliding force by means of a claw body through hole formed in the radial slide mechanism sub-claw body and a penetrating pressing body that penetrates this claw body through hole via a displacement allowance and is attached to the clamp base, thereby enabling the sub-claw body to be displaced radially with a simple configuration.

[0009] This is how it was configured Features of the invention According to the invention, the sub-collet chuck is configured such that the radial slide mechanism is provided with a pressing elastic body between the sub-jaw body and the penetrating pressing body for elastically pressing the sub-jaw body against the clamp base, so that the sub-jaw body easy The rotor can be displaced reciprocally in the radial direction.

[0010] Another feature of the present invention is that the sub-collet chuck further includes a release mechanism that applies a force to elastically displace adjacent sub-jaw bodies in a direction to release the gripped object.

[0011] According to another feature of the present invention configured in this manner, the sub-collet chuck has an opening mechanism that applies a force to elastically displace adjacent sub-claw bodies in the direction of releasing the grasped object, so that the sub-claw bodies can release the grasped object at the same time as the claw portion releases the grasped object, thereby improving the operability of each of the operations of attaching and removing the grasped object.

[0012] Another feature of the present invention is that in the sub-collet chuck, the clamp base further has a positioning pin that is inserted into the object to be gripped to determine the position of the object to be gripped.

[0013] According to another feature of the present invention configured in this manner, the sub-collet chuck has a positioning pin that is inserted into the object to be gripped by the clamp base to determine the position of the object to be gripped, thereby facilitating the positioning of the object to be gripped and improving the operability and processing accuracy of the mounting operation.

[0014] Another feature of the present invention is that in the sub-collet chuck, the clamp base is disposed between at least two divided jaw portions.

[0015] According to another feature of the present invention configured in this manner, the sub-collet chuck is disposed between at least two claw portions which are divided into two parts of the clamp base, so that the sub-collet chuck can be configured compactly without becoming too large. [Brief description of the drawings]

[0018] [Figure 1] 1 is a front view showing the outline of the configuration of a sub-collet chuck according to the present invention in a state where it is attached to a collet body of a collet chuck. FIG. [Diagram 2]2 is a side cross-sectional view of the collet chuck to which the sub-collet chuck is attached, as viewed from line 2-2 in FIG. 1. [Diagram 3] 3 is a partial enlarged view showing the configuration within a dashed circle 3 shown in FIG. 2. [Figure 4] 3 is a side cross-sectional view showing a state in which the sub-jaw body is removed from the sub-collet chuck shown in FIG. 2 and a large object is gripped by the gripping portion. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] An embodiment of a sub-collet chuck according to the present invention will be described below with reference to the drawings. Fig. 1 is a front view showing the outline of the configuration of a sub-collet chuck 200 according to the present invention attached to a collet body 101 of a collet chuck 100. Fig. 2 is a side cross-sectional view of the collet chuck 100 to which the sub-collet chuck 200 is attached, as seen from line 2-2 in Fig. 1. The sub-collet chuck 200 is a mechanical device that is attached to the collet chuck 100 provided on a spindle that is driven to rotate in a machine tool such as a lathe, milling machine, or machining center, and detachably holds an object to be grasped WK.

[0020] Before describing the sub collet chuck 200, we will describe the collet chuck 100 to which the sub collet chuck 200 is attached. The collet chuck 100 is a mechanical device for detachably holding the sub collet chuck 200, and is attached to the spindle of a machine tool (not shown). The collet chuck 100 includes a collet body 101.

[0021] The collet body 101 is a component that presses the sub-claw body 201 of the sub-collet chuck 200 against the object to be grasped WK, and is made of a metal material formed into a cylindrical shape. More specifically, the collet body 101 is mainly composed of a base portion 102, a tilting portion 103, and a claw portion 104.

[0022] Base 102 is formed in a cylindrical shape, and a female thread is formed on its inner circumferential surface into which holder nut 107, which will be described later, is screwed. Tilting portions 103 are portions that extend and protrude in the axial direction from six positions equally spaced circumferentially on one end face (the right side in the figure) of both end faces of base 102, which is formed in a cylindrical shape, and are formed in a plate shape that is curved along the outer circumferential surface of base 102. These six tilting portions 103 are formed with elasticity that allows them to flex inward and outward with respect to the central axis of collet body 101.

[0023] The claw portions 104 are portions that press the sub-claw bodies 201, and are formed so as to protrude from one end of each of the six inclined portions 103 toward the outside and inside in the radial direction of the collet body 101. In this case, the outer peripheral surface 104a of each of the six claw portions 104 is formed in a tapered shape that spreads outward in the radial direction from the inclined portion 103 side toward the end side of the claw portion 104 in order to slide on a collet guide 105, which will be described later. Also, the inner peripheral surface 104b of each of the six claw portions 104 is formed into an arc surface with an inner diameter slightly larger than the outer diameter of the three sub-claw bodies 201.

[0024] In addition, when the sub-collet chuck 200 is not attached to the collet chuck 100, the claw portion 104 can grip an object WK having a larger diameter than the object WK gripped by the sub-collet chuck 200.

[0025] The collet guide 105 is a component for displacing the six claws 104 inward while holding the collet body 101 slidably in the axial direction of the collet body 101, and is configured by forming a metal material into a cylindrical shape. A guide-side sliding surface 105a is formed on the inner peripheral portion of one end portion (the right side in the figure) of the collet guide 105. The guide-side sliding surface 105a is a portion on which the six outer peripheral surfaces 104a of the collet body 101 slide to displace each of the claws 104 inward, and is formed to taper outward in the axial direction. The collet guide 105 is formed such that one end portion (the right side in the figure) of the collet guide 105 protrudes in a flange-like shape, and this protruding portion is fixed to the end face of the outer cylinder 106 by a bolt.

[0026] External cylinder 106 is a component that holds collet guide 105 in a housed state, and is made by forming a metal material into a cylindrical shape. The end face of this external cylinder 106 opposite to the side where collet guide 105 is attached (the left side in the figure) is attached to the spindle of the machine tool via a bolt (not shown).

[0027] The holder nut 107 is a component for moving the collet body 101 back and forth in the direction of the central axis of the collet body 101, and is configured with protruding portions 107a that protrude radially outward from six positions in the circumferential direction of the outer periphery of a metallic cylinder. These six protruding portions 107a are portions that screw into the inner periphery of the base 102 of the collet body 101, and are formed with male threads. The outer periphery of the cylinder of the holder nut 107 is held by a clamp base receiver 109 with a drawbar connector 108 attached inside the cylinder.

[0028] The drawbar connector 108 is a component for connecting the tip of the drawbar DB extending from the spindle of the machine tool to the holder nut 107, and is configured by forming a metal material into a cylindrical shape. The tip of the drawbar DB is screwed into the inside of one end side (the left side in the figure) of this drawbar connector 108, and the entire drawbar connector 108 is housed in the holder nut 107 in a slidable state.

[0029] The clamp base receiver 109 is a component that supports the clamp base 210 while housing the holder nut 107 in a state in which it can advance and retreat in the central axis direction of the holder nut 107, and is formed into a flange shape with one end (the left side in the figure) of a metallic cylinder. This clamp base receiver 109 has through holes formed in a part of the cylinder through which the six protruding parts 107a pass. In addition, the flange part 109a of the clamp base receiver 109 that protrudes radially outward is fitted to the inner peripheral surface of the collet guide 105, and supports the clamp base 210 at the end opposite to the flange part 109a.

[0030] (Configuration of sub collet chuck 200) The sub-collet chuck 200 includes a sub-jaw body 201. The sub-jaw body 201 is a component for gripping the object to be gripped WK, and is composed of at least two block bodies made of metal or resin. Specifically, the sub-jaw body 201 is composed of three block bodies made of metal that press and grip the outer periphery of the object to be gripped WK from three sides. Each of these sub-jaw bodies 201 has a gripping portion 201a, a pressure receiving portion 201b, a base surface 201c, a work surface 201d, and a jaw body through hole 202 formed therein.

[0031] The gripping portion 201a is a portion that presses a part of the outer periphery of the gripped object WK, and is formed in a shape corresponding to the shape of the gripped portion of the gripped object WK. In this embodiment, the gripping portion 201a is formed of a concavely recessed arc-shaped curved surface. The pressure-receiving portion 201b is a portion that receives a pressing force from the claw portion 104 of the collet body 101, and is formed of a convexly protruding arc-shaped curved surface. This pressure-receiving portion 201b may be formed of a curved surface with the same curvature as the claw portion 104, but in this embodiment, it is formed of a curved surface with a curvature larger than that of the claw portion 104.

[0032] The base surface 201c is a portion that is abutted against the clamp base 210, and is composed of a flat surface formed between the gripping portion 201a and the pressure receiving portion 201b. The work surface 201d is a portion that is abutted against the object to be grasped WK, and is composed of a flat surface that is formed between the gripping portion 201a and the pressure receiving portion 201b in a state facing the base surface 201c.

[0033] The claw through hole 202 is a portion through which a penetrating pressing body 205, which will be described later, penetrates, and is configured as a through hole that extends parallel to the axial direction of the collet body 101 relative to the sub-claw body 201 and opens to the base surface 201c and the work surface 201d. This claw through hole 202 is configured to have a small diameter portion 202a, a large diameter portion 202b, and an intermediate bottom portion 202c.

[0034] The small diameter portion 202a is formed with an inner diameter larger than that of the large diameter portion 202b of the penetrating pressing body 205. In this case, the inner diameter of the small diameter portion 202a is formed with a size that allows the sub-claw body 201 to move from a state in which it is not gripping the object to be grasped WK to a state in which it is gripping the object to be grasped WK. The large diameter portion 202b is formed with an inner diameter larger than that of the pressing elastic body and the head of the penetrating pressing body 205. In this case, the inner diameter of the large diameter portion 202b is formed with a size that allows the sub-claw body 201 to move from a state in which it is not gripping the object to be grasped WK to a state in which it is gripping the object to be grasped WK.

[0035] That is, the claw body through hole 202 is formed to have a size that allows a displacement S between the penetrating pressing body 205 and the sub-claw body 201 to displace from a state in which it is not gripping the object to be gripped WK to a state in which it is gripping the object to be gripped WK. Also, the large diameter portion 202b is formed to have a length (depth) that can accommodate the pressing elastic body and the head of the penetrating pressing body 205.

[0036] The intermediate bottom portion 202c is a portion against which one end (the left side in the figure) of the pressing elastic body of the penetrating pressing body 205 is pressed, and is formed in a flat annular shape. In addition, an open elastic body accommodating portion 203 is formed on the side surface of this sub-claw body 201.

[0037] The release elastic body accommodating section 203 is a section for accommodating the release elastic body 204, and is formed with openings on both side surfaces facing the work surface 201d and the sub-claw body 201 arranged adjacently. In this case, the opening portion of the release elastic body accommodating section 203 on the work surface 201d is closed by a lid body 203a. The lid body 203a is a part for preventing the release elastic body 204 accommodated in the release elastic body accommodating section 203 from falling off, and is configured in the form of a metal plate. The lid body 203a is screwed in a state where it is flush with the work surface 201d. Note that the lid body 203a is not shown in FIG. 1.

[0038] The release elastic body 204 is a component for separating two adjacent sub-claw bodies 201 from each other to release the grip of the object WK to be grasped, and is disposed between the two adjacent sub-claw bodies 201. In this embodiment, the release elastic body 204 is configured by a metal coil spring. Therefore, the release elastic body 204 is housed and held in the release elastic body housing portions 203 formed in the two adjacent sub-claw bodies 201, both ends of which are respectively housed and held.

[0039] The penetrating pressing body 205 is a part for attaching the sub-claw body 201 in a state where it is elastically pressed against the clamp base 210, and is formed in a rod shape made of metal or resin. More specifically, as shown in Fig. 3, the penetrating pressing body 205 has a small diameter portion 205a, a large diameter portion 205b, and a head portion 205c.

[0040] The small diameter portion 205a is a portion that passes through the claw body through hole 202 and is screwed into the clamp base 210, and is configured by forming a male thread on the outer circumferential surface of a shaft. The large diameter portion 205b is a portion that is disposed within the claw body through hole 202, and is configured by a shaft having an outer diameter larger than that of the small diameter portion 205a. A pressing elastic body 206 is provided on the outer circumferential portion of this large diameter portion 205b.

[0041] Head 205c is a portion in which a hexagonal hole is formed for fitting a hexagonal wrench for rotating penetrating pressing body 205 around its axis, and for positioning pressing elastic body 206 on the outer periphery of large diameter portion 205b, and is formed in a cylindrical shape with an outer diameter larger than the outer diameters of large diameter portion 205b and pressing elastic body 206. That is, in this embodiment, penetrating pressing body 205 is configured by a bolt.

[0042] The pressing elastic body 206 is a part for elastically pressing the sub-claw body 201 against the clamp base 210, and is constituted by a metallic coil spring. The pressing elastic body 206 is disposed on the outside of the large diameter portion 205b of the penetrating pressing body 205, and one end (the left side in the figure) presses the intermediate bottom portion 202c, while the other end (the right side in the figure) presses the head portion 205c of the penetrating pressing body 205, thereby elastically pressing the sub-claw body 201 against the clamp base 210.

[0043] The clamp base 210 is a component for detachably holding each of the three sub-claw bodies 201 and for determining the axial position of the object to be grasped WK when each of the three sub-claw bodies 201 is not being held, and is configured by forming a metal material into a cylindrical shape. One end of the clamp base 210 in the axial direction (left side in the figure) is a portion that abuts against the end face of the clamp base receiver 109, and a fitting portion 210a that protrudes in an annular shape and fits into the end face of the clamp base receiver 109 is formed in the center. Meanwhile, the other end of the clamp base 210 in the axial direction (right side in the figure) is a sub-collet receiving portion 210b against which the sub-claw body 201 is attached.

[0044] In this case, the sub-collet receiving portion 210b is formed with a female screw into which the small diameter portion of the penetrating pressing body 205 is screwed. Furthermore, the clamp base 210 has a work accommodating portion 211 formed in the center along the axial direction, and a positioning pin 212 is provided facing the work accommodating portion 211. The work accommodating portion 211 is a portion that accommodates a part of the object to be grasped WK, and is composed of a bottomed hole that opens into the sub-collet receiving portion 210b.

[0045] The positioning pin 212 is a component for determining the position of the object WK to be gripped by the sub-collet chuck 200, and is configured by forming a metal or resin material into a thin rod shape with a pointed tip. The positioning pin 212 is held in a state in which it can slide freely in the axial direction within a through hole formed in the center of the clamp base 210 so that its tip protrudes into the workpiece accommodating portion 211. In this case, the positioning pin 212 is elastically pressed toward the workpiece accommodating portion 211 by a spring 213 provided at the rear end of the positioning pin 212.

[0046] Spring 213 is composed of a coil spring, one end (left side in the figure) of which is fitted into bottom plate 214 attached via a bolt in fitting portion 210a, and the other end (right side in the figure) of which is fitted into the rear end of positioning pin 212. This clamp base 210 is detachably attached to clamp base receiver 109 by bolt 215 which passes through clamp base 210.

[0047] (Operation of sub collet chuck 200) Next, the operation of the sub-collet chuck 200 configured as above will be described. This sub-collet chuck 200 is attached to a spindle (not shown) of a machine tool (e.g., a lathe) that performs machining such as cutting on the object to be grasped WK. In this case, the sub-collet chuck 200 is attached to the collet chuck 100 that is attached to the machine tool.

[0048] First, the operator prepares a set of sub-collet chucks 200 consisting of three sub-jaw bodies 201 and one clamp base 210. In this case, the three sub-jaw bodies 201 are prepared without the lid body 203a and the release elastic body 204 attached thereto. Also, the clamp base 210 is prepared with the positioning pin 212 attached thereto.

[0049] Next, the worker attaches the clamp base 210 to the clamp base receiver 109. Specifically, the worker fits the fitting portion 210a of the clamp base 210 into the clamp base receiver 109, and then attaches the clamp base 210 to the clamp base receiver 109 using the bolts 215. Next, the worker attaches the three sub-claw bodies 201 to the clamp base 210, respectively.

[0050] Specifically, the worker attaches the three sub-claw bodies 201 in a circular arrangement on the sub-collet receiving portion 210b of the clamp base 210 via the penetrating pressing bodies 205. In this case, the pressing elastic body 206 is attached to the outside of the large diameter portion 205b of each penetrating pressing body 205. In this case, the sub-claw bodies 201 are attached to the clamp base 210 so that the gaps between the sub-claw bodies 201 match the gaps between the claw portions 104 and connect both gaps in the radial direction, thereby improving the dischargeability of cutting chips. Next, the worker places the opening elastic body 204 in the opening elastic body accommodating portions 203 facing each other between two adjacent sub-claw bodies 201, and covers each opening elastic body accommodating portion 203 with the lid body 203a.

[0051] As a result, the three sub-claw bodies 201 are pressed in a direction away from each other by the three release elastic bodies 204. In this case, each of the three sub-claw bodies 201 is elastically attached to the clamp base 210 by the penetrating pressing body 205, and a displacement allowance S is formed between the claw body through hole 202 and the penetrating pressing body 205. Therefore, each of the three sub-claw bodies 201 slides on the sub-collet receiving portion 210b of the clamp base 210 in a direction away from each other by the elastic force of the release elastic body 204. That is, in the sub-collet chuck 200, each of the three sub-claw bodies 201 is displaced radially outward so that a circular area surrounded by each of the gripping portions 201a of the three sub-claw bodies 201 is maximized.

[0052] Next, the worker prepares the object WK to be grasped and causes the sub-collet chuck 200 to grasp it. Specifically, the worker inserts the portion of the object WK to be grasped into the center of the three sub-jaw bodies 201 arranged in a circular ring shape to position it in the workpiece storage section 211. In this case, if the object WK has a center hole for positioning, the worker can regulate the radial position of the sub-collet chuck 200 with respect to the object WK by inserting the positioning pin 212 protruding into the workpiece storage section 211 into the center hole. In this case, the worker pushes the object WK against the elastic force of the spring 213 of the positioning pin 212 to abut against the workpiece surface 201d of the sub-jaw body 201. It is to be noted that the object WK does not necessarily have to have a center hole.

[0053] Next, the worker closes the claw portions 104 of the collet chuck 100. Specifically, the worker operates the machine tool to pull the drawbar DB to the left side in the figure. As a result, in the collet chuck 100, the outer peripheral surfaces 104a of the six claw portions 104 slide on the guide-side sliding surface 105a of the collet guide 105, so that the claw portions 104 tilt radially inward and press the three sub-claw bodies 201 radially inward.

[0054] In this case, the three sub-claw bodies 201 are elastically attached to the clamp base 210 by the penetrating pressing body 205, and a displacement allowance S is formed between the claw body through-hole 202 and the penetrating pressing body 205. Therefore, the three sub-claw bodies 201 slide on the sub-collet receiving portion 210b of the clamp base 210 in the direction approaching each other while resisting the elastic force of the release elastic body 204.

[0055] In this case, each sub-jaw body 201 is displaced along the sub-collet receiving portion 210b of the clamp base 210, so that the entire sub-jaw body 201 moves parallel to the radial direction. That is, the claw body through-hole 202, the penetrating pressing body 205 and the pressing elastic body 206 correspond to the radial slide mechanism according to the present invention. As a result, the sub-collet chuck 200 grips the outer periphery of the object to be gripped WK with the entire gripping portion 201a of each of the three sub-jaw bodies 201.

[0056] Next, the worker performs machining on the object to be grasped WK. Specifically, the worker operates the machine tool to rotate the main shaft, thereby rotating the object to be grasped WK via the collet chuck 100 and the sub-collet chuck 200, and also brings a blade (not shown) provided on the machine tool into contact with the object to be grasped WK to perform machining such as cutting. In this machining, the object to be grasped WK is firmly gripped by the sub-collet chuck 200.

[0057] Next, when the operator has finished machining the object to be gripped WK, he or she operates the machine tool to push out the drawbar DB and displace it to the right in the figure. As a result, the collet chuck 100 displaces to the right in the figure of the collet body 101, and the six claw portions 104 spread outward in the radial direction. In this case, the three sub-claw bodies 201 of the sub-collet chuck 200 are displaced outward in the radial direction by the elastic force of the release elastic body 204, since the pressing force of the claw portions 104 of the collet chuck 100 weakens. That is, in the sub-collet chuck 200, the sub-claw bodies 201 open together with the opening of the claw portions 104 of the collet chuck 100.

[0058] This allows the worker to remove the object to be grasped WK gripped by the three sub-jaw bodies 201 from the sub-collet chuck 200. In this case, the elastic force of the spring 213 of the positioning pin 212 makes it easier for the worker to pull the object to be grasped WK out from inside the three sub-jaw bodies 201. This allows the worker to finish processing the object to be grasped WK. Then, when the worker wants to perform machining on another object to be grasped WK, the worker can have the sub-collet chuck 200 grip the new object to be grasped WK in the same manner as described above.

[0059] The worker can also process the object to be grasped WK with the sub-jaw body 201 removed. Specifically, the worker removes the sub-jaw body 201 from the clamp base 210 by removing the penetrating pressing body 205 from the clamp base 210. Next, as shown in FIG. 4, the worker inserts a part of the object to be grasped WK2 into the workpiece accommodation portion 211 of the clamp base 210 and engages the positioning pin 212, and operates the machine tool to pull the drawbar DB to the left side in the figure.

[0060] As a result, the collet chuck 100 has the six claws 104 whose outer circumferential surfaces 104a slide on the guide-side sliding surface 105a of the collet guide 105, causing each of the claws 104 to tilt radially inward and grip the outer circumferential portion of the object to be gripped WK. This allows the worker to operate the machine tool to perform machining on the object to be gripped WK. That is, the sub-collet chuck 200 can grip the object to be gripped WK2 whose gripping portion has a different size. In addition, the worker can grip the object to be gripped WK2 even when the clamp base 210 is removed from the clamp base receiver 109.

[0061] As can be understood from the above operation description, according to the above embodiment, the sub-collet chuck 200 has multiple sub-claw bodies 201 that are arranged on the side of the claw portion 104 of the collet chuck 100 that grips the object to be gripped WK, and are capable of reciprocating displacement in the radial direction of the collet chuck 100 via a radial slide mechanism.When the claw portion 104 is tilted, the sub-claw bodies 201 move parallel to the radial direction, so that the object to be gripped WK can be gripped by surface contact, and damage such as pressure marks can be suppressed on the gripping portion.

[0062] Furthermore, the present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the scope of the present invention. In the description of the modified examples, the same reference numerals are used for the same parts as those in the above-described embodiment that are not newly designated by reference numerals.

[0063] For example, in the above embodiment, the collet chuck 100 is configured to include six claw portions 104. However, the collet chuck 100 may be configured to include claw portions 104 that are divided into at least two or more in the circumferential direction.

[0064] In the above embodiment, the sub-collet chuck 200 is configured to include three sub-jaw bodies 201. However, the sub-collet chuck 200 may be configured to include at least two or more sub-jaw bodies 201.

[0065] In the above embodiment, the sub-collet chuck 200 is configured such that each sub-claw body 201 is elastically displaced in the direction to release the gripped object WK by the release elastic body 204. That is, the release elastic body 204 corresponds to the release mechanism according to the present invention. However, the sub-collet chuck 200 may be configured without the release elastic body 204.

[0066] In the above embodiment, the radial slide mechanism according to the present invention is configured by the claw body through hole 202, the penetrating pressing body 205, and the pressing elastic body 206. However, the radial slide mechanism according to the present invention only needs to be configured to be able to reciprocate the sub-claw body 201 in the parallel direction. Therefore, the radial slide mechanism can be configured by the claw body through hole 202 and the penetrating pressing body 205, for example, without the pressing elastic body 206. In this case, the penetrating pressing body 205 is fastened to the clamp base 210 with a fastening force that allows the sub-claw body 201 to be displaced relative to the clamp base 210.

[0067] In addition, the radial slide mechanism can also be configured so that the claw portion 104 and the sub-claw body 201 are fixed to each other via an elastic material such as an elastomer or rubber material, and the base surface 201c of the sub-claw body 201 slides on the sub-collet receiving portion 210b of the clamp base 210.

[0068] In the above embodiment, the gripping portion 201a of the sub-claw body 201 is formed in a concave arc shape. However, the sub-claw body 201 may be formed in any shape that can grip the object WK to be gripped. Therefore, the gripping portion 201a of the sub-claw body 201 may be in a convex arc shape, a polygonal shape such as a triangle, or a non-geometric shape (irregular shape). The gripping portion 201a may not be integral with the sub-claw body 201, but may be formed separately so that gripping portions 201a of various shapes can be attached.

[0069] In the above embodiment, the pressing elastic body 206 is configured with a coil spring. However, the pressing elastic body 206 may be configured to elastically press the sub-claw body 201 against the clamp base 210. Therefore, the pressing elastic body 206 may be configured with, for example, a cylindrical elastomer or rubber material having elasticity.

[0070] In the above embodiment, the sub-collet chuck 200 is configured to include the positioning pin 212. However, the sub-collet chuck 200 may be configured without the positioning pin 212.

[0071] In the above embodiment, the sub-collet chuck 200 is configured so that the sub-jaw bodies 201 grip the outer periphery of the object to be gripped WK. However, the sub-collet chuck 200 can also be configured so that the sub-jaw bodies 201 grip the hole of the object to be gripped WK from the radially inner side toward the outer side. In this case, the sub-collet chuck 200 can have the clamp base 210 disposed outside the claw portion 104. In this case, the release mechanism of the sub-collet chuck 200 can be configured with coil springs that pull the adjacent sub-jaw bodies 201 against each other.

[0072] In the above embodiment, a lathe is assumed as the machine tool to which the sub collet chuck 200 is attached. However, the sub collet chuck 200 can be attached to various machine tools other than lathes, such as milling machines, machining centers, grinding machines, drilling machines, and hobbing machines, and can also be attached to inspection devices and measuring devices that inspect and measure the object to be grasped WK. The sub collet chuck 200 can also be attached to devices or equipment that grip the object to be grasped WK other than machine tools. For example, the sub collet chuck 200 can be attached to a hand that grips the object to be grasped WK in an articulated robot (not shown). [Explanation of symbols]

[0073] WK, WK2...Gripped object, DB...Drawbar, S...Displacement allowance, 100...Collet chuck, 101...collet body, 102...base, 103...inclination portion, 104...claw portion, 104a...outer peripheral surface, 104b...inner peripheral surface, 105...collet guide, 105a...guide side sliding surface, 106...outer cylinder, 107...holder nut, 107a...projection portion, 108...drawbar connector, 109...clamp base receiver, 109a...flange portion, 200...Sub collet chuck, 201...sub-claw body, 201a...gripping portion, 201b...pressure receiving portion, 201c...base surface, 201d...work surface, 202...claw body through hole, 202a...small diameter portion, 202b...large diameter portion, 202c...middle bottom portion, 203...open elastic body accommodating portion, 203a...lid body, 204...open elastic body, 205...penetrating pressing body, 205a...small diameter portion, 205b...large diameter portion, 205c...head portion, 206...pressing elastic body, 210... clamp base, 210a... fitting portion, 210b... sub-collet receiving portion, 211... workpiece accommodating portion, 212... positioning pin, 213... spring, 214... bottom plate, 215... bolt.

Claims

1. A sub-collet chuck is attached to a collet chuck having a collet body with a claw portion divided into at least two in a circumferential direction at one end side of a cylindrical body, the claw portion being inclined in a radial direction, and is adapted to grip an object to be gripped, At least two sub-jaw bodies arranged adjacent to the side of the claw portion that grips the object to be gripped and grip the object to be gripped; a clamp base that supports the sub-claw body via a radial slide mechanism for reciprocatingly displacing the sub-claw body in the radial direction of the cylindrical body in response to a pressing force applied to the sub-claw body by the claw portion of the collet body tilting in the radial direction, The radial slide mechanism includes: A claw body through hole penetrating the sub-claw body; a through-pressing body that passes through the claw body through-hole and is attached to the clamp base to press the sub-claw body against the clamp base; a pressing elastic body between the sub-claw body and the penetrating pressing body for elastically pressing the sub-claw body against the clamp base; The claw body through hole is The hole is formed to have a size that allows the sub-claw body to be displaced relative to the other claw body. The penetrating pressing body is The sub-collet chuck is characterized in that the sub-jaw body is pressed against the clamp base with a force allowing the sub-jaw body to slide.

2. The sub-collet chuck according to claim 1, further comprising: A sub-collet chuck comprising: a release mechanism that applies a force to elastically displace adjacent sub-jaw bodies in a direction to release the object to be gripped.

3. The sub-collet chuck according to claim 1 or 2, further comprising: The clamp base is A sub-collet chuck comprising: a positioning pin that is inserted into the object to be gripped to determine the position of the object.

4. In the sub-collet chuck according to any one of claims 1 to 3, The clamp base is A sub-collet chuck characterized in that it is disposed between the at least two divided jaw portions.

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