JP2008500191A - Hydraulic chuck - Google Patents

Abstract

A chuck comprising a body (1) defining a hydraulic fluid receiving container (6) and a tool receiving portion (4) having at least one deformable wall (41). The hydraulic fluid receiving container and the tool receiving portion have a structure in which the deformable wall portion is deformed by the pressure applied to the hydraulic fluid in the hydraulic fluid receiving vessel and the inserted tool can be gripped. . Furthermore, the chuck comprises a movable piston (8). The movable piston (8) is partially disposed in the hydraulic fluid receiving container and is movable between a first position and a second position. Further, the capacity in the hydraulic fluid receiving container that is replaced by the movable member when the movable piston (8) is in the first position is the hydraulic fluid that is replaced by the movable piston when the movable piston is in the second position. Featuring less than the capacity in the receiving container. Further, the chuck includes centrifugal operation pressure increasing means (9) for increasing the hydraulic pressure of the injected hydraulic fluid depending on the turning speed of the chuck. The centrifugal operation pressure increasing means is structured to act on the movable piston. The movable piston has a complementary taper (85) and the centrifugally actuated boosting means comprises a jaw (92) having a complementary taper. The jaw (92) is structured to be driven outward by a centrifugal effect, and further, when driven outward in this way, interacts with the tapered portion (85) of the movable piston (8), The movable piston is driven in a direction that functions so as to increase the capacity in the hydraulic fluid receiving container (6) replaced by the movable piston (8).

Description

Detailed Description of the Invention

The present invention relates to a hydraulic chuck, and more particularly to a hydraulic chuck used in high speed machining operations.
In the conventional precision tool gripping method, the shank of the tool is fixed with a tapered collet. The taper collet is pulled back toward the main shaft taper by the spring force in the axial direction, and a high gripping force is applied to the tool shank. Such a device was appropriate when the turning speed was slow. However, in applications where the turning speed is very fast and very high accuracy is required, the performance of conventional tapered collet chucks is reduced and alternatives are required.

  When the spindle speed increases, the spindle taper also opens due to centrifugal force. Furthermore, the spindle taper expands faster than the collet expansion. The collet tends to be pulled further into the taper by the spring force. However, at present, the gripping force on the tool spindle is weakened due to a decrease in tension of the spring. As a result, there may be a speed at which the gripping force on the tool spindle becomes zero due to the taper expansion. For this reason, excessive escape and tool slip occur, and the tool is finally completely released. As the gripping force further decreases, the collet chuck and the tool partially sway and may generate strong vibrations.

  Further, in such a collet chuck, a problem may occur when trying to achieve very high accuracy. That is, the collet taper, hole, and spindle taper need to be machined individually. Also, it is very difficult to machine these parts with sufficient accuracy to achieve the currently required runout.

  Further, such a collet chuck relies on a sliding motion between the collet and the spindle taper when a tool is attached to and detached from the chuck. Generally, oil is applied to the contact surface. However, since the oil dries and centrifuges from the contact surface, maintenance is required to periodically apply the oil. Such maintenance is disadvantageous because it causes machine downtime and requires skilled operation.

  Also, there are additional problems with conventional collet chuck designs. That is, if the number of start-ups is very large, the strength of the spring used to pull the collet into the main shaft taper is lost to some extent, the performance is lowered, and eventually cracking may occur due to fatigue.

Accordingly, there is a need to devise alternative aspects of the chuck.
According to one aspect of the present invention, there is provided a chuck comprising a hydraulic fluid receiving container, a tool receiving portion, and means for applying pressure to the hydraulic fluid when the hydraulic fluid is injected into the hydraulic fluid receiving container. Provided. The tool receiving portion has at least one deformable wall. In the hydraulic fluid receiving container and the tool receiving portion, the deformable wall portion is deformed by the pressure applied to the hydraulic fluid in the hydraulic fluid receiving vessel, and the inserted tool is gripped by the deformation of the deformable wall portion. It has a structure.

    The pressure application unit may include a movable member. The movable member may be partially disposed within the hydraulic fluid receiving container and movable between the first position and the second position. In this case, the capacity in the hydraulic fluid receiving container replaced by the movable member when the movable member is in the first position is smaller than the capacity in the hydraulic fluid receiving container replaced by the movable member when in the second position. It is characterized by.

  In such a case, the hydraulic pressure of the hydraulic fluid provided in the hydraulic fluid receiving container tends to be high when the movable member is in the second position. Furthermore, when the pressure in the hydraulic fluid receiving container rises, the deformable wall portion is deformed, and the gripping force on the inserted tool tends to increase.

  Here, the expression “partially (in the hydraulic fluid receiving container)” is used to refer to one element having a portion in the hydraulic fluid receiving container. That is, a portion within the hydraulic fluid receiving container means replacing the volume within the hydraulic fluid receiving container rather than merely forming part of the outer boundary of the hydraulic fluid receiving container. Thus, for example, a plug or screw that plugs the fill port into the hydraulic fluid receiving container is not considered to be in the hydraulic fluid receiving container. Also, the plug or screw that plugs the filling port into the hydraulic fluid receiving container usually cannot replace the capacity in the hydraulic fluid receiving container.

  The movable member may have a structure that slides between the first position and the second position. The movable member may be a piston. The movable member may have a first portion having a first cross-sectional area and a second portion having a second cross-sectional area. The diameter of the movable member may vary along the longitudinal direction. The first portion may have a first diameter and the second portion may have a second diameter.

  When the movable member and the hydraulic fluid receiving container move in one direction between the first position and the second position, the amount of the first portion of the movable member disposed in the hydraulic fluid receiving container is reduced. When the amount of the second portion of the movable member disposed in the hydraulic fluid receiving container increases, the movable member moves in the other direction between the first position and the second position, and is disposed in the hydraulic fluid receiving container. The amount of the first part of the movable member to be increased may be increased, and the amount of the second part of the movable member disposed in the hydraulic fluid receiving container may be decreased.

  The pressure application unit may be a pressure control unit. In the pressure control means, the gripping force to the inserted tool may be controlled by making it possible to select the degree of pressure applied to the working fluid in the working fluid receiving container. The pressure control means may include the movable member.

  The pressure applying unit may include a centrifugal operation pressure increasing unit. The centrifugal operation pressure increasing means may be a centrifugal operation, and may increase the pressure depending on the turning speed of the chuck. The centrifugal operation pressure increasing means may be structured to act on the pressure control means.

  The centrifugal operation pressure increasing means may be structured to act on the movable member. The movable member may have a tapered portion. The centrifugal operation pressure increasing means may have at least one complementary taper portion. The complementary taper portion may be configured to be driven outward by a centrifugal effect. Further, the complementary tapered portion may have a structure that interacts with the tapered portion of the movable member to drive the movable member when driven in the outward direction. In this case, the movable member may be driven in a direction in which the capacity in the hydraulic fluid receiving container replaced by the movable member increases. Such an operation of the complementary taper portion is considered to tend to increase the hydraulic pressure of the injected hydraulic fluid.

A portion of the hydraulic fluid receiving container may be defined by a deformable wall.
The tool receiving part may have three deformable walls. Each of the deformable wall portions or each deformable wall portion may have a land that contacts the inserted tool. The lands, or each land, may have an abutment surface that closely matches the shape of the shank of the tool being inserted. The land or each land may have a contact surface having a concave cross section. The contact surface may contact the shank of the tool to be inserted.

The abutment surface may be machined to a final shape by a general drilling process performed at the tool receiving portion.
According to another aspect of the invention, a chuck is provided having a body defining a hydraulic fluid receiving container. The chuck includes a tool receiving portion having at least one deformable wall. The hydraulic fluid receiving container and the tool receiving portion have a structure in which the deformable wall portion is deformed by the pressure applied to the hydraulic fluid in the hydraulic fluid receiving container and the inserted tool is gripped. The chuck further includes a movable member. The movable member is partially disposed within the hydraulic fluid receiving container. The movable member is movable between a first position and a second position. In this case, the capacity in the hydraulic fluid receiving container replaced by the movable member when the movable member is in the first position is the hydraulic fluid receiving container replaced by the movable member when the movable member is in the second position. It is characterized by being less than the internal capacity.

  According to another aspect of the invention, a chuck is provided having a body defining a hydraulic fluid receiving container. The chuck includes a tool receiving portion having at least one deformable wall. The hydraulic fluid receiving container and the tool receiving portion have a structure in which the deformable wall portion is deformed by the pressure applied to the hydraulic fluid in the hydraulic fluid receiving container and the inserted tool is gripped. The chuck further includes a movable member. The movable member is partially disposed within the hydraulic fluid receiving container. The movable member moves between a first position and a second position. In this case, the capacity in the hydraulic fluid receiving container replaced by the movable member when the movable member is in the first position is the capacity in the hydraulic fluid receiving container replaced by the movable member when the movable member is in the second position. Featuring less than. The chuck includes centrifugal operation pressure increasing means, and increases the hydraulic pressure of the injected hydraulic fluid depending on the rotation speed of the chuck. The centrifugal operation pressure increasing means has a structure that acts on the movable member. The movable member has a tapered portion. Further, the centrifugal operation pressure increasing means has at least one complementary taper portion. The complementary taper portion is structured to be driven outward by a centrifugal effect. Further, the complementary taper portion is configured to interact with the taper portion of the movable member and drive the movable member when driven outward in this manner. In this case, the movable member is driven in a direction in which the capacity in the hydraulic fluid receiving container replaced by the movable member increases.

  According to another aspect of the present invention, the step of providing hydraulic fluid to the chuck, the step of operating the chuck to release the hydraulic pressure of the hydraulic fluid injected into the hydraulic fluid receiving container, and the tool in the tool receiving portion. There is provided a tool gripping method including a step of inserting, and a step of pressurizing a working fluid in a chuck to deform a deformable wall portion and abut against the inserted tool.

  According to another aspect of the present invention, a method for manufacturing the chuck having a tool receiving portion is provided. The tool receiving portion has a plurality of deformable walls. Each deformable wall has a tool contact land. This chuck manufacturing method includes a step of forming a plurality of lands by drilling a tool contact surface by a general drilling process.

Embodiments of the present invention will be described below using an example with reference to the accompanying drawings.
FIG. 1 is a schematic view of a chuck including a main body or core 1 to which a protruding portion 2 and a rear shaft portion 3 are welded. A tool receiving portion 4 in which a tool 5 can be disposed is provided inside the main body or the core 1.

  As can be clearly seen from FIG. 2, the tool receiving part 4 comprises three deformable wall parts 41. The deformable wall portions 41 are connected to each other and form a triangular prism. Each of the deformable walls 41 has a tool contact land 42 having a concave tool contact surface. In FIG. 2, it is apparent that the tool contact land 42 is in contact with the tool 5 to be supported. FIG. 1 clearly shows that the tool 5 is in contact with one of the tool contact lands 42. It should be noted that in the direction shown in FIG. 1, this tool abutment land is located at the top of the tool. On the other hand, in FIG. 1, the land which is in contact with the lower part of the tool is not shown. This is because the other two tool contact lands 42 are in contact with the upper land 120 degrees apart. Therefore, the other two tool contact lands 42 are not shown in the cross-sectional view shown in FIG.

  This tool contact surface is formed by general drilling as part of the final stage of chuck manufacture. In the drilling process, a drilling tool is inserted into the tool receiving portion, and the tool contact land 42 is drilled into a predetermined size and shape by the drilling tool. By this drilling process, the tool contact land is precisely machined so that the shaft portion of the tool manufactured to be held by the chuck is closely engaged with the tool contact land.

  A hydraulic fluid chamber 61 is arranged on each side surface of the plurality of deformable wall portions 41 opposite to the side surface having the tool contact land 42. The hydraulic fluid chamber 61 forms a part of the hydraulic fluid receiving container 6. The hydraulic fluid receiving container 6 will be described in detail below.

  The main body or core 1 has a piston receiving hole 7 at the opposite end in addition to the tool receiving portion 4. The piston 8 is gripped by a rear cover portion (end cover) 71 in the piston receiving hole 7. Both the piston receiving hole 7 and the end cover 71 define an outer boundary of the extension portion of the hydraulic fluid receiving container 6. The piston 8 is therefore partly arranged in the hydraulic fluid receiving container 6.

  Further, the main body or the core 1 is provided with a passage or a tunnel 62. The passage or tunnel 62 has a function of connecting the hydraulic fluid chamber 61 adjacent to the plurality of deformable walls 41 and the piston receiving hole 7. Accordingly, a hydraulic fluid flow path is provided between the piston receiving hole 7 and the hydraulic fluid chamber 61 adjacent to the plurality of deformable wall portions 41. The protrusion 2 is provided with a hydraulic fluid receiving container filling port 63. The filling port is provided with a screw plug stopper 64.

  The spring 81 is attached to the piston 8. Although a coil spring is shown in FIG. 1, it is often a wave spring in practice. Wave springs are more resistant to high-speed turning than conventional coil springs. The spring 81 is located between a spring terminal sleeve 82 attached to the main body of the core 1 and a spring fixing portion 83 provided on the piston 8. The spring 81 has a function of urging the piston 8 in the right direction (the direction shown in FIG. 1). As will be described in detail below, this corresponds to the position where pressure is applied to the working fluid in the working fluid receiving container 6. In this way, the plurality of deformable wall portions 41 tend to deform. The inserted tool 5 is gripped by the deformation of the deformable wall portions 41.

As will be described in detail below, a centrifugal operation pressure increasing means 9 is disposed at the inner end of the piston 8.
Sealing means 84 is provided to the piston 8 in a region where the piston 8 penetrates the end cover 71 and a region where the piston 8 penetrates the spring end sleeve 82. The sealing means 84 has a function of preventing the working fluid in the working fluid receiving container 6 from leaking from the rear part of the chuck or from leaking into the front centrifugal working pressure increasing means 9. The sealing means may be an O-ring seal, for example.

  The piston 8 has two main parts 8a and 8b. These two main parts are arranged in the hydraulic fluid receiving container 6. These main portions are located on either side of the spring fixing portion 83. The first main portion 8a is a portion to which a spring 81 is attached and has a diameter A. The second main portion 8b is located on the other side of the spring fixing portion 83, and has a diameter B smaller than the diameter A of the first main portion 8a.

  It should be noted that a portion of the first main portion 8a fits within the spring end sleeve 82 and a portion of the second main portion 8b fits within the end cover 71. These portions that are accommodated in the spring end portion 81 and the end cover 71 do not contribute to the change in the capacity in the hydraulic fluid receiving container 6, and therefore are not considered to be accommodated in the hydraulic fluid receiving container 6.

  Since these two parts have different diameters (A and B), when the piston 8 moves in the axial direction with respect to the main body or the core 1, the total capacity in the hydraulic fluid receiving container 6 occupied by the piston 8 changes.

  Specifically, when the piston 8 moves to the right from the position shown in FIG. 1, more part of the second main portion 8b of the piston moves toward the hole of the end cover 71, and the piston 8 A greater portion of the first main portion 8a of the second end moves out of the hole in the spring end sleeve 82. Furthermore, since the diameter A of the first main portion 8a is larger than the diameter B of the second main portion 8b, this movement increases the capacity occupied by the piston 8 in the hydraulic fluid receiving container 6. Instead, the volume that the hydraulic fluid can occupy decreases and the pressure in the hydraulic fluid increases. Thereafter, when the piston 8 returns in the left direction (the direction shown in FIG. 1), the situation is reversed and the hydraulic pressure of the working fluid decreases.

  Thus, the hydraulic pressure of the hydraulic fluid changes due to the movement of the piston 8, and as a result, the pressure sensed in the hydraulic fluid chamber 61 adjacent to the plurality of deformable wall portions 41 due to the movement of the piston 8. It can be changed. Due to such a change in the hydraulic pressure, the plurality of deformable wall portions 41 are loosened as the hydraulic pressure is decreased, and are deformed as the hydraulic pressure is increased, so that the inserted tool can be firmly gripped.

  Therefore, in the basic setting up and operation of the apparatus, after assembling the parts, the push rod (not shown) is used to oppose the force of the spring 81 to move the piston 8 to the position shown in FIG. Then, the hydraulic fluid is pushed into the hydraulic fluid receiving container 6. Then, the screw plug stopper 64 is inserted into the hydraulic fluid filling port 63 and sealed. At this point, when the action of the push rod (not shown) is removed from the piston 8, the piston 8 tends to move in the right direction (the direction shown in FIG. 1) due to the action of the spring 81. For this reason, the capacity | capacitance which a hydraulic fluid can occupy in the hydraulic fluid receiving container 6 reduces. Thereby, instead, the plurality of deformable wall portions 42 of the tool receiving portion 4 tend to deform, and in this state, it is impossible to insert the tool 5. Now you are ready to use the chuck.

  When the push rod (not shown) is used again in the tool insertion process, the piston 8 is pushed toward the position shown in FIG. 1, and the hydraulic pressure in the hydraulic fluid receiving container 6 is reduced. As a result, the plurality of deformable wall portions 42 are loosened, and a tool can be inserted. Once the tool 5 is inserted, the action of the push rod is removed, and the piston 8 moves again in the right direction (direction shown in FIG. 1) by the spring action, and a plurality of deformations are caused by the hydraulic pressure of the working fluid. The possible wall 41 is deformed and abuts against the tool inserted via the respective tool abutment lands 42 and grips the inserted tool.

  If the tool 5 is to be removed, the push rod is used again and the piston 8 is pushed towards the position shown in FIG. 1 to reduce the hydraulic fluid pressure and loosen the plurality of deformable walls 41. To.

  Although not shown in detail in the drawing, the mechanism for moving the piston 8 to operate the push rod to allow tool insertion and removal is part of the overall design of the chuck, You may arrange. More generally, however, the push rod mechanism is attached to a machine on which the chuck is also mounted. The push rod does not rotate at the same time as the chuck body, but only needs to abut against the end of the piston 8 when the chuck is stationary.

  Since the structure and operation of the basic components of this apparatus have been described in detail, the structure and operation of the centrifugal operation pressure increasing means 9 will be described in detail. The innermost end of the piston 8 is adjacent to the centrifugally acting pressure increasing means. A tapered hole 85 is provided at the innermost end of the piston 8. The centrifugally operating pressure increasing means mechanism 9 has an internal taper body 91 and a plurality of taper wedge jaws 92. The plurality of taper wedge jaws 92 are supported by the inner taper body 91, so that the plurality of taper wedge jaws 92 can move outward and radially due to the influence of centrifugal force. The tapered surfaces of the plurality of tapered wedge jaws 92 complement a tapered hole 85 provided at the end of the piston 8. Accordingly, the plurality of tapered wedge jaws 92 move outward due to the influence of centrifugal force, and the piston 8 is moved in the right direction (FIG. 1) by the interaction between the plurality of tapered wedge jaws 92 and the internal taper 85 of the piston 8. Move in the direction indicated by That is, the piston 8 is moved by the centrifugal operation pressure increasing means 9, and a larger portion of the large diameter portion 8a enters the hydraulic fluid receiving container 6 and is replaced with a corresponding portion of the small diameter portion 8b. For this reason, the capacity in the hydraulic fluid receiving container 6 is reduced. Accordingly, the hydraulic pressure of the hydraulic fluid increases, and the deformation of the plurality of deformable wall portions 41 is further promoted.

  Preferably, as the swivel speed of the device increases (if the swivel speed of the device does not increase, the tool will tend to slip due to the stronger force involved, or the chuck will tend to move away from the tool gradually). However, the pressure applied by the centrifugal operation pressure-increasing means 9 increases, and the gripping force on the tool 5 tends to increase due to the increase in the hydraulic pressure. Thereby, the tendency for the force which grips the tool 5 to loosen can be stopped. Of course, the centrifugal force applied to the plurality of tapered wedge jaws 92 increases as the turning speed of the chuck increases. Further, the moving range of the piston 8 is also increased. Furthermore, with the decrease in the turning speed, a process opposite to the process accompanying the increase in the turning speed occurs, and the gripping force decreases.

  Of course, preferably, since the oil generally used as the hydraulic fluid is incompressible, the change in the volume in the hydraulic fluid receiving container 6 is relatively small, but the hydraulic pressure rises remarkably. As a result, the gripping force can be significantly increased.

  It should be noted that the spring end sleeve 82 is provided as a separate part attached to the core or body 1. For this reason, it is an advantage that the stop position of the piston 8 in the assembly can be determined based on the length of the spring end sleeve 82. Thereby, the magnitude of the pressure applied to the hydraulic fluid when the piston 8 is at this stop position can be determined.

  As described above, the plurality of tool contact lands 42 are finished to a final size by drilling after assembling the chuck. Further, in order to minimize the vibration, such a processing may be performed after the completed assembly is fixed with a bearing dedicated to the completed assembly.

  When the main body or the core 1 is manufactured, the tool receiving portion 4 is machined from a solid blank (in a non-hollow state) by wire electric discharge machining (EDM). Thereafter, the solid blank is turned to perform drilling, thereby defining the outer shape. Thereby, piston 8 which is an assembly part can be stored.

  It should also be noted that the cross section of the tool receiving portion (or “collet”) of the present apparatus is the same over the entire length compared to a conventional tapered collet. That is, the outer surface of the plurality of deformable wall portions 41 forms a substantially triangular prism, and the surface of the tool contact land 42 produced by drilling becomes the boundary of the cylindrical cavity that receives the tool 5.

It is a longitudinal cross-sectional view of a chuck | zipper. It is II-II sectional drawing of the chuck | zipper shown by FIG.

Claims (23)

A hydraulic fluid receiving container; a tool receiving portion having at least one deformable wall; and means for applying pressure to the hydraulic fluid when the hydraulic fluid is injected into the hydraulic fluid receiving container. In the chuck, the working fluid receiving container and the tool receiving portion are deformed by the pressure applied to the working fluid in the working fluid receiving container, and the deformed wall portion is deformed, and the tool inserted as a result. A chuck characterized in that the chuck is configured to be gripped. The pressure application means includes centrifugal operation pressure increase means,
The chuck according to claim 1, wherein the centrifugal operation pressure increasing means is a means for increasing a pressure depending on a turning speed of the chuck. The pressure applying means includes a movable member,
The chuck according to claim 2, wherein the centrifugal operation pressure-intensifying means has a structure acting on the movable member. The movable member includes a tapered portion,
The chuck according to claim 3, wherein the centrifugal operation pressure increasing means has at least one complementary taper portion. The complementary taper portion is a structure that is driven outward by a centrifugal effect,
Further, when the complementary tapered portion is driven outward in this way,
Interacts with the tapered portion of the movable member;
Driving the movable member in a direction to fulfill its function during use,
The chuck according to claim 4, wherein the chuck is configured to promote deformation of the deformable wall portion. The movable member is movable between a first position and a second position;
6. The capacity of the hydraulic fluid receiving container is larger when the movable member is in the first position than when the movable member is in the second position. 6. Chuck. The chuck according to claim 3, wherein the movable member is partially disposed in the hydraulic fluid receiving container. A chuck according to claim 7 when dependent on claim 6, comprising:
The capacity in the hydraulic fluid receiving container replaced by the movable member when the movable member is in the first position is in the hydraulic fluid receiving container replaced by the movable member when the movable member is in the second position. A chuck characterized by being smaller than the capacity of the chuck. The chuck according to claim 3, wherein the movable member is a piston. The movable member has a first portion and a second portion,
The chuck according to claim 3, wherein the first portion has a first cross-sectional area, and the second portion has a second cross-sectional area. A chuck according to claim 10 when dependent on claim 8, comprising:
The movable member and the hydraulic fluid receiving container are:
When the movable member moves in one direction between the first position and the second position, the amount of the first portion of the movable member disposed in the hydraulic fluid receiving container decreases, and the hydraulic fluid receiving container While the amount of the second portion of the movable member disposed within increases,
When the movable member moves in the other direction between the first position and the second position, the amount of the first portion of the movable member disposed in the hydraulic fluid receiving container increases, and the hydraulic fluid receiving container The chuck is characterized in that the amount of the second portion of the movable member disposed in the inside is reduced. The pressure application means includes pressure control means for controlling a gripping force on the inserted tool by making it possible to select a degree of pressure to be applied to the injected hydraulic fluid. The chuck according to any one of the above. A chuck according to any one of claims 1 to 12 when dependent on claim 3,
The chuck characterized in that the movable member is slidably movable. A chuck according to any one of claims 1 to 13 when dependent on claim 3,
The movable member has a structure that moves in an axial direction with respect to a chuck body. The chuck according to claim 1, wherein a part of the hydraulic fluid receiving container is defined by the deformable wall portion. The chuck according to any one of claims 1 to 15, wherein the tool receiving portion has three deformable wall portions. The chuck according to any one of claims 1 to 16, wherein each of the deformable wall portion or each deformable wall portion has a land that abuts against an inserted tool. The chuck according to claim 17, wherein the land or each land has an abutment surface that closely matches a shape of a shank of a tool to be inserted. The chuck according to claim 18, wherein the plurality of contact surfaces are machined into a final shape by a general drilling process performed in the tool receiving portion. A chuck having a body defining a hydraulic fluid receiving container,
The chuck has a tool receiving portion with at least one deformable wall,
The hydraulic fluid receiving container and the tool receiving portion are configured such that the deformable wall portion is deformed by the pressure applied to the hydraulic fluid in the hydraulic fluid receiving vessel and the inserted tool can be gripped. And
The chuck further includes a movable member,
The movable member is partially disposed in the hydraulic fluid receiving container,
The movable member is movable between a first position and a second position;
The capacity in the hydraulic fluid receiving container that is replaced by the movable member when the movable member is in the first position is the capacity in the hydraulic fluid receiving container that is replaced by the movable member when the movable member is in the second position. A chuck characterized by being less than the capacity of. A chuck having a body defining a hydraulic fluid receiving container,
The chuck has a tool receiving portion with at least one deformable wall,
The hydraulic fluid receiving container and the tool receiving portion are configured such that the deformable wall portion is deformed by the pressure applied to the hydraulic fluid in the hydraulic fluid receiving vessel and the inserted tool can be gripped. And
The chuck further includes a movable member,
The movable member is partially disposed in the hydraulic fluid receiving container,
The movable member is movable between a first position and a second position;
The capacity in the hydraulic fluid receiving container that is replaced by the movable member when the movable member is in the first position is the capacity in the hydraulic fluid receiving container that is replaced by the movable member when the movable member is in the second position. Less than the capacity of
The chuck further includes centrifugal operation pressure increasing means,
The centrifugal operation pressure increasing means increases the hydraulic pressure of the injected hydraulic fluid depending on the turning speed of the chuck,
The centrifugal operation pressure increasing means is a structure acting on the movable member,
The movable member has a tapered portion,
The centrifugal operation pressure increasing means has at least one complementary taper portion;
The complementary taper portion is a structure that is driven outward by a centrifugal effect,
The complementary tapered portion further has a structure in which, when driven in the outward direction, abuts against the tapered portion of the movable member to drive the movable member,
In this case, the movable member is driven in a direction that functions so as to increase the capacity of the hydraulic fluid receiving container replaced by the movable member. A method of gripping a tool,
a) injecting a working fluid into the chuck according to any one of claims 1 to 21;
b) actuating the chuck to release the hydraulic pressure of the hydraulic fluid injected into the hydraulic fluid receiving container;
c) inserting the tool into the tool receiving portion;
d) pressurizing the working fluid in the chuck to deform the deformable wall and bring it into contact with the inserted tool. A method for manufacturing a chuck according to any one of claims 1 to 21,
The chuck has a tool receiving portion,
The tool receiving portion has a plurality of deformable wall portions,
Each of the plurality of deformable wall portions has a tool contact land,
The manufacturing method includes a step of forming a plurality of lands by drilling a tool contact surface by a general drilling process.

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