Hydraulic clamping device and method for manufacturing the same

Abstract

In a hydraulic clamping device, the concentricity, cylindricity and roundness of a cylindrical part are improved to achieve high-precision clamping. A hydraulic clamping device is provided, wherein a working fluid chamber (40) is defined between a main body (12) and a thin-walled cylindrical part (30) fitted on the outer periphery of the main body (12), and the cylindrical part (30) is deformed by expanding the diameter by the pressure of the working fluid sealed in the working fluid chamber (40), thereby clamping a clamped part (W1), wherein the device comprises: an O-ring (38) disposed between the main body (12) and the cylindrical part (30) at various positions on the outside of the two ends in the axial direction of the working fluid chamber (40); and an adhesive layer (32) disposed between the main body (12) and the cylindrical part (30) at various positions on the outside in the axial direction than two O-rings (38) in order to fix the cylindrical part (30) to the main body (12).

Description

Technical Field

[0001] The invention relates to a hydraulic clamping device and a manufacturing method of the hydraulic clamping device. Background Art

[0002] As a hydraulic clamping device, there is known a mandrel-type hydraulic clamping device, which includes a rod-shaped main body with a circular cross-sectional shape, and a thin-walled cylindrical member mounted on the outer peripheral surface of the main body, and a cylindrical working fluid chamber is formed between the main body and the cylindrical member (for example, Patent Document 1). The hydraulic clamping device pressurizes the working fluid sealed in the working fluid chamber to expand the diameter of the cylindrical member, thereby clamping the clamped part arranged on the outer periphery of the cylindrical member.

[0003] In such a hydraulic clamping device, the cylindrical member is required to be fixed to the main body, and the working fluid chamber is required to be liquid-tight. In fixing the cylindrical member to the main body, the cylindrical member is often pressed into the main body (for example, Patent Documents 2 and 3). Regarding the liquid-tightness of the working fluid chamber, there are also known working fluid chambers that use an elastic sealing ring or adhesive as a sealing member provided between the main body and the cylindrical member (for example, Patent Documents 2 to 4).

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Publication No. 58-21605

[0007] Patent Document 2: JP-A-63-46177

[0008] Patent Document 3: Japanese Patent Publication No. 1-60365

[0009] Patent document 4: DE3816562A1 publication Summary of the invention

[0010] Problems to be solved by the invention

[0011] Regarding the hydraulic clamping device that fixes the cylindrical component to the body by press-fitting, there is a limit to improving the concentricity, cylindricity, and roundness of the cylindrical component due to the influence of stress, and it is difficult to perform clamping with higher precision.

[0012] The problem to be solved by the present invention is to improve the concentricity, cylindricity and roundness of a cylindrical member in a hydraulic clamping device and to perform clamping with higher precision.

[0013] Means for solving problems

[0014] (1) A hydraulic clamping device according to an embodiment of the present invention comprises: a first component having a first circular circumferential surface; and a second component having a second circumferential surface engaged with the first circumferential surface, wherein a working fluid chamber is defined by a recessed portion provided on at least one of the first circumferential surface and the second circumferential surface, and the second component is elastically deformed in a radial direction by the pressure of the working fluid sealed in the working fluid chamber, thereby clamping the clamped component, wherein the hydraulic clamping device comprises: an annular sealing component provided between the first component and the second component at respective positions further outward than both ends in the axial direction of the working fluid chamber, and forming a pair with the working fluid chamber sandwiched in the axial direction; and an adhesive layer provided between the first component and the second component at respective positions further outward in the axial direction than the paired annular sealing components, and forming a pair with the working fluid chamber sandwiched in the axial direction, in order to fix the second component to the first component.

[0015] According to this structure, since there is no influence of stress, the concentricity, cylindricity, and roundness of the cylindrical member are high, and clamping with higher precision can be performed.

[0016] (2) In the above-mentioned hydraulic clamping device, it is preferred that at least one of the first circumferential surface and the second circumferential surface has an adhesive groove, which is arranged on both sides of the axial direction of the working fluid chamber and is paired with the working fluid chamber sandwiched in the axial direction, and the adhesive layer is formed by the adhesive filled in each of the paired adhesive grooves.

[0017] According to this configuration, the thickness of the adhesive layer can be reliably set with high uniformity according to the depth of the adhesive groove.

[0018] (3) In the above-mentioned hydraulic clamping device, preferably, one of the pair of adhesive grooves is provided in the first member, and the other is provided in the second member.

[0019] According to this structure, it is possible to prevent the adhesive in the adhesive groove from being improperly attached to the first member when the second member is assembled (inserted) into the first member.

[0020] (4) In the above-mentioned hydraulic clamping device, it is preferred that the first component has an expanded diameter portion or a reduced diameter portion defining an end face opposite to the end face of the second component, the adhesive groove on the expanded diameter portion or the reduced diameter portion side of the pair of adhesive grooves is arranged on the first component, and the adhesive groove on the opposite side of the expanded diameter portion or the reduced diameter portion of the pair of adhesive grooves is arranged on the second component.

[0021] According to this structure, it is possible to prevent the adhesive in the adhesive groove from being improperly attached to the first member when the second member is assembled (inserted) into the first member.

[0022] (5) In the above-mentioned hydraulic clamping device, preferably, the adhesive grooves each include a spiral groove.

[0023] According to this structure, the second member can be reliably fixed to the first member in both the axial direction and the circumferential direction.

[0024] (6) In the above-mentioned hydraulic clamping device, preferably, each of the adhesive grooves has a triangular cross-section defined by an inclined surface and a vertical surface.

[0025] According to this configuration, when the second member is assembled to the first member, the adhesive in the adhesive groove is unlikely to overflow outside the adhesive groove, and the adhesive is likely to remain in the adhesive groove.

[0026] (7) In the above-mentioned hydraulic clamping device, preferably, the first component or the second component has a plurality of annular O-ring grooves formed on the first peripheral surface or the second peripheral surface, and the sealing components each include an O-ring made of an elastic body and fitted into the O-ring groove.

[0027] According to this configuration, the working fluid chamber is sealed liquid-tightly by the O-ring, and the second member is centered relative to the first member by the O-ring, so that the concentricity between the first member and the second member is improved.

[0028] (8) In the above-mentioned hydraulic clamping device, it is preferred that, in order to inhibit the adhesive of the adhesive layer from invading the configuration portion of the sealing component, an adhesive blocking portion is provided at an axial position between the sealing component and the adhesive layer on the corresponding side, wherein the gap between the first circumferential surface and the second circumferential surface is smaller than the gap at other axial positions.

[0029] According to this configuration, it is possible to suppress adhesion of the adhesive to the sealing member, and the sealing member can stabilize the liquid-tight sealing performance of the working fluid chamber.

[0030] (9) In the above-mentioned hydraulic clamping device, preferably, each of the adhesive stoppers includes a shoulder portion formed on the first member by expanding the diameter.

[0031] According to this configuration, it is possible to suppress the adhesive of the adhesive layer from intruding into the portion where the sealing member is disposed without requiring any additional member.

[0032] (10) In the above-mentioned hydraulic clamping device, preferably, the adhesive stopper includes an O-ring made of elastic body and provided on the first member or the second member.

[0033] According to this configuration, the O-ring prevents the adhesive of the adhesive layer from intruding into the portion where the seal member is disposed.

[0034] (11) In the above-mentioned hydraulic clamping device, preferably, the first component or the second component has a plurality of annular O-ring grooves formed on the first circumferential surface or the second circumferential surface, the sealing components respectively include O-rings made of an elastomer and engaged with the O-ring grooves, and an adhesive blocking portion having a gap between the first circumferential surface and the second circumferential surface that is smaller than the gap at other axial positions at the axial position between the sealing component and the adhesive layer, and the adhesive blocking portion respectively includes a ring component, which is arranged along the side surface of the O-ring groove on the opposite side to the working fluid chamber when viewed in the axial direction, and has a portion protruding radially from the O-ring groove.

[0035] According to this configuration, the ring member suppresses the adhesive of the adhesive layer from intruding into the arrangement portion of the seal member, and suppresses abnormal deformation of the O-ring.

[0036] (12) In the above-mentioned hydraulic clamping device, preferably, the first member includes a shoulder portion formed by expanding the diameter at a position farther from the working fluid chamber than the pair of adhesive layers in the axial direction.

[0037] According to this configuration, the gap between the main body and the cylindrical member is maintained at an optimum level over the entire circumference, and the thickness of the adhesive layer is suppressed from varying in the circumferential direction.

[0038] (13) In the above-mentioned hydraulic clamping device, it is preferred that the first member and the second member are made of different types of materials, and that, for example, the elastic modulus and wear resistance of the second member are higher than those of the first member.

[0039] According to this structure, the performance of the second member can be made different from that of the first member, and high expansion property, wear resistance, etc. can be specialized.

[0040] (14) In the above-mentioned hydraulic clamping device, preferably, the first member is made of metal, and the second member is made of fiber-reinforced plastic having a higher elastic modulus than the metal constituting the first member.

[0041] According to this configuration, the second member can have a different performance from that of the first member and can have particularly high expandability.

[0042] (15) In the above-mentioned hydraulic clamping device, preferably, the first component includes a rod-shaped portion, the first circumferential surface is the outer circumferential surface of the rod-shaped portion, and the second component includes a cylindrical portion, the second circumferential surface is the inner circumferential surface of the cylindrical portion, and the cylindrical portion is deformed and expanded in diameter by the pressure of the working fluid, thereby clamping the clamped component on the outer circumferential surface of the cylindrical body.

[0043] According to this configuration, in the mandrel-type clamping device, high-precision clamping can be performed.

[0044] (16) In the above-mentioned hydraulic clamping device, preferably, the first component includes a first outward flange portion, the second component includes a second outward flange portion opposite to the first outward flange portion, and an additional adhesive layer is provided between the opposing surfaces of the first outward flange portion and the second outward flange portion.

[0045] According to this structure, the bonding strength of the second member to the first member is improved.

[0046] (17) In the above-mentioned hydraulic clamping device, preferably, the first component includes an opening extending along the axial direction, the first circumferential surface is the inner circumferential surface of the opening, the second component includes a cylindrical portion, the second circumferential surface is the outer circumferential surface of the cylindrical portion, and the cylindrical portion is deformed and reduced in diameter by the pressure of the working fluid, thereby clamping the clamped component on the inner circumferential surface of the cylindrical body.

[0047] According to this configuration, in the chuck type clamping device, high-precision clamping can be performed.

[0048] (18) In the above-mentioned hydraulic clamping device, it is preferred that it also has: a piston chamber, which is formed in the first component and connected to the working fluid chamber; a threaded hole, which is formed in the first component and connected to the piston chamber; a piston, which is movably arranged in the piston chamber; and a working threaded component, which is screwed into the threaded hole, and the hydraulic clamping device includes a pressurizing structure, which moves the piston in the piston chamber by screwing in the working threaded component, thereby pressurizing the working fluid in the working fluid chamber.

[0049] According to this configuration, there is no need to exchange or pressurize the working fluid from the outside, and the working fluid in the working fluid chamber can be pressurized by the hydraulic clamp alone.

[0050] (19) A manufacturing method of a hydraulic clamping device according to one embodiment of the present invention is the above-mentioned manufacturing method of the hydraulic clamping device, wherein the first component and the second component are engaged with each other by moving the first component and the second component relative to each other in the axial direction, and the adhesive layer in the pair of adhesive layers, which is located at a position further forward than any of the sealing components when viewed in the moving direction of the second component relative to the first component, is formed on the first component before the first component and the second component are engaged with each other, and the adhesive layer which is located at a position further rearward than any of the sealing components when viewed in the moving direction, is formed on the second component before the engagement.

[0051] According to this manufacturing method, when the second member is assembled (inserted) into the first member, the adhesive layer does not come into contact with the sealing member, and the adhesive does not adhere to the sealing member during assembly.

[0052] Effects of the Invention

[0053] According to the hydraulic clamping device of the present invention, the concentricity, cylindricity and roundness of the cylindrical member are improved, and clamping with higher precision can be performed. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 It is a longitudinal sectional view showing the first embodiment of the hydraulic clamping device of the present invention.

[0055] Figure 2 It is a longitudinal sectional view showing a second embodiment of the hydraulic clamping device of the present invention.

[0056] Figure 3 It is a longitudinal sectional view showing a third embodiment of the hydraulic clamping device of the present invention.

[0057] Figure 4 It is a longitudinal sectional view showing a fourth embodiment of the hydraulic clamping device of the present invention.

[0058] Figure 5 It is a longitudinal sectional view showing a fifth embodiment of the hydraulic clamping device of the present invention.

[0059] Figure 6 It is a longitudinal sectional view showing an assembly process of the hydraulic clamping device according to the fifth embodiment.

[0060] Figure 7 It is a longitudinal sectional view showing a sixth embodiment of the hydraulic clamping device of the present invention.

[0061] Figure 8 It is a longitudinal sectional view showing a seventh embodiment of the hydraulic clamping device of the present invention.

[0062] Fig. 9It is a longitudinal sectional view showing an eighth embodiment of the hydraulic clamping device of the present invention.

[0063] Fig.10 It is a longitudinal sectional view showing a ninth embodiment of the hydraulic clamping device of the present invention.

[0064] Fig.11 It is a longitudinal sectional view showing a tenth embodiment of the hydraulic clamping device of the present invention.

[0065] Fig.12 It is a longitudinal sectional view showing the eleventh embodiment of the hydraulic clamping device of the present invention.

[0066] Fig.13 It is a longitudinal sectional view showing another embodiment of the hydraulic clamping device of the present invention. DETAILED DESCRIPTION

[0067] Below, refer to Figure 1 Embodiment 1 of the hydraulic clamping device of the present invention will be described.

[0068] The hydraulic clamping device 10 is a mandrel type clamping device, such as Figure 1 As shown, it has a main body (first component) 12. The main body 12 has a first shaft end 14, a main shaft portion 16, a flange portion (expanded diameter portion) 18 and a second shaft end 20 in sequence along the axial direction on the same axis, including a rod-shaped portion with a circular cross-sectional shape. The first shaft end 14 and the second shaft end 20 have the same outer diameter. The main shaft portion 16 has an outer diameter larger than the first shaft end 14 and the second shaft end 20. The flange portion 18 has an outer diameter larger than the main shaft portion 16, and is an outward flange portion (first outward flange portion) that expands radially outward relative to the main shaft portion 16, constituting a stopper that abuts to set the axial configuration position of the cylindrical component 30 and the clamped component W1 described later.

[0069] A thin-walled cylindrical member (second member) 30 is fixed to the outer periphery of the main spindle portion 16 by an adhesive layer 32. The cylindrical member 30 has an inner peripheral surface (second peripheral surface) 30A that fits with the outer peripheral surface (first peripheral surface) 16A of the main spindle portion 16; an outer peripheral surface 30B that clamps the cylindrical clamped member W1; and an annular end surface 30C that faces the disc-shaped end surface 18A of the flange portion 18 in the axial direction. The outer diameter OD1 of the outer peripheral surface 16A of the main spindle portion 16 is smaller than the inner diameter ID1 of the inner peripheral surface 30A of the cylindrical member 30. (Inner diameter ID1)-(Outer diameter OD1) can be about 50 to 150 μm. In addition, the details of the fixing (bonding) of the cylindrical member 30 to the main spindle portion 16 by the adhesive layer 32 will be described later.

[0070] Circumferential groove-shaped recessed portions 16B and 30D are formed at the same position in the axial direction on the outer circumferential surface 16A of the main spindle portion 16 and the inner circumferential surface 30A of the cylindrical member 30. The recessed portions 16B and 30D define a working fluid chamber 40 having an annular cross-sectional shape between the main spindle portion 16 and the cylindrical member 30, and the working fluid chamber 40 has a predetermined length in the axial direction and extends across the entire circumference of the outer circumferential surface 16A of the main spindle portion 16.

[0071] The adhesive layer 32 is provided in pairs at intervals along the axial direction at the fitting portion where the outer circumferential surface 16A of the main spindle portion 16 and the inner circumferential surface 30A of the cylindrical member 30 fit together, and two adhesive layers 32 are provided on both sides of the working liquid chamber 40 separated from the axial end of the working liquid chamber 40 along the axial direction, and the main body 12 and the cylindrical member 30 are fixed to each other by bonding (adhering). The adhesive layer 32 is formed by an adhesive filled in an adhesive groove 34, and the adhesive groove 34 is formed by a circumferential groove formed on the outer circumferential surface 16A of the main spindle portion 16. As a preferred adhesive for forming the adhesive layer 32, there are two-component epoxy adhesives, anaerobic adhesives, etc.

[0072] The thickness of each adhesive layer 32 formed by the adhesive filling each adhesive groove 34 is determined by a value of 1 / 2 of a value obtained by subtracting the outer diameter OD2 of the adhesive groove from the inner diameter ID1 of the inner circumferential surface 30A of the cylindrical member 30. That is, the thickness of the adhesive layer 32 is reliably set with high uniformity according to the depth of the adhesive groove 34.

[0073] The optimum thickness of each adhesive layer 32 is determined by the maximum shear strength, which is determined by the type of adhesive, etc. The optimum axial dimension of each adhesive layer 32 is determined by the outer diameter OD1 of the outer peripheral surface 16A of the mandrel main portion 16, etc.

[0074] The cylindrical member 30 is assembled with respect to the main body 12 as follows: First, an uncured liquid adhesive is applied and filled in each adhesive groove 34 of the spindle main portion 16, and an O-ring 38 is installed in each O-ring groove 36 described later. Thereafter, the cylindrical member 30 is moved from the end surface 14A side of the first shaft end portion 14 relative to the main body 12 in the axial direction until the end surface 30C of the cylindrical member 30 abuts against the end surface 18A of the flange portion 18, and the inner peripheral surface 30A of the cylindrical member 30 is fitted with the outer peripheral surface 16A of the spindle main portion 16.

[0075] The end face 30C of the cylindrical member 30 abuts against the end face 18A of the flange portion 18, thereby uniquely determining the assembly position of the cylindrical member 30 in the axial direction of the main body 12. In addition, when the assembly position of the cylindrical member 30 in the axial direction of the main body 12 is determined based on the use of other jigs, etc., the end face 30C of the cylindrical member 30 does not need to abut against the end face 18A of the flange portion 18.

[0076] In the fitting portion where the outer peripheral surface 16A of the main spindle part 16 and the inner peripheral surface 30A of the cylindrical member 30 are fitted, an O-ring groove 36 formed by a circumferential groove is formed on the outer peripheral surface 16A of the main spindle part 16 between each adhesive layer 32 and the corresponding axial end of the working fluid chamber 40. An O-ring 38 made of an elastomer constituting a sealing member is installed in each O-ring groove 36. Each O-ring 38 abuts against the inner peripheral surface 30A of the cylindrical member 30 in an elastically compressed manner to perform a liquid-tight seal of the working fluid chamber 40.

[0077] In other words, the hydraulic clamping device 10 has a sealing member composed of annular O-rings 38 arranged between the main body 12 and the cylindrical member 30 and paired with each other in the axial direction sandwiching the working fluid chamber 40 at each position on the outside of the two ends in the axial direction of the working fluid chamber 40. Furthermore, in order to fix the cylindrical member 30 relative to the main body 12, the hydraulic clamping device 10 has a pair of adhesive layers 32 arranged between the main body 12 and the cylindrical member 30 at each position on the outside of the two O-rings 38 (pair of sealing members) in the axial direction.

[0078] The two O-rings 38 are located at positions separated from each other in the axial direction, and are in elastic compression contact with the inner circumferential surface 30A of the cylindrical part 30 across the entire circumference, thereby centering the cylindrical part 30 relative to the main part of the spindle 16 and improving the concentricity of the main part of the spindle 16 and the cylindrical part 30.

[0079] The mandrel main portion 16 has an outer diameter OD3 larger than that of the outer peripheral surface 16A, that is, a shoulder portion 42 formed by expanding the diameter, between the arrangement portion of each O-ring 38 and the adhesive layer 32 adjacent to the arrangement portion, at the fitting portion fitted with the cylindrical member 30. The fitting clearance of the shoulder portion 42 generated by the difference between the inner diameter ID1 of the inner peripheral surface 30A of the cylindrical member 30 and the outer diameter OD3 of the shoulder portion 42 is smaller than the fitting clearance of other portions, that is, the difference between the outer diameter OD1 of the outer peripheral surface 16A and the inner diameter ID1 of the inner peripheral surface 30A of the cylindrical member 30.

[0080] The fitting clearance between the shoulder portion 42 and the cylindrical member 30 is small, and thus the shoulder portion 42 functions as an adhesive stopper that prevents the adhesive of the adhesive layer 32 from intruding into the portion where the O-ring 38 is disposed, thereby suppressing adhesion of the adhesive to the O-ring 38 .

[0081] The main body 12 has a piston chamber 50 extending in the axial direction across the first shaft end 14 and the main shaft portion 16 on the central axis. The piston 52 is fitted in the piston chamber 50 in a manner that can move in the axial direction. One end of the piston chamber 50 is connected to the working fluid chamber 40 through an axial passage 54 formed in the main shaft portion 16 and a plurality of radial passages 56. In addition, for the convenience of drilling, the passage 54 opens at the end face 20A of the second shaft end 20 through a drilling hole 66, but the opening is liquid-tightly blocked by a threaded plug 69 that is screwed with the second shaft end 20 and uses a steel ball 68 as a sealing component.

[0082] The chamber space on the passage 54 side of the piston chamber 50 partitioned by the piston 52 , the passages 54 , 56 , and the working fluid chamber 40 form a closed space, and working oil (working fluid) such as grease is sealed therein.

[0083] A threaded hole 58 extending in the axial direction and communicating with the other end of the piston chamber 50 and a tool insertion hole 60 communicating with the threaded hole 58 and opening at the end surface 14A of the first shaft end 14 are formed on the central axis of the first shaft end 14. A working threaded member 62 with a hexagonal hole is screwed into the threaded hole 58. A steel ball 64 is arranged between the working threaded member 62 and the piston 52. The working threaded member 62 is screwed into the threaded hole 58 toward the piston chamber 50 side, and the piston 52 is moved forward (in Figure 1 Observed as moving in the axial direction to the left).

[0084] This constitutes a pressurizing structure, and the piston 52 moves toward the passage 54 side (at the piston chamber 50) through the forward movement of the working screw member 62. Figure 1 By this movement, the working oil in the working fluid chamber 40 is pressurized, and the pressure of the working oil increases. By the increase in the pressure of the working oil, the cylindrical member 30 is deformed to expand radially outward in an elastically deformed state.

[0085] Thus, the clamped component W1 is clamped on the outer peripheral surface 30B of the cylindrical component 30 based on the diameter expansion deformation of the cylindrical component 30. More specifically, the clamped component W1 has a center hole A fitted in the outer periphery of the cylindrical component 30, and the outer peripheral surface 30B of the cylindrical component 30 is closely attached to the inner peripheral surface of the center hole A by the diameter expansion deformation of the cylindrical component 30, so that the clamped component W1 is fixed (clamped) to the hydraulic clamping device 10.

[0086] In the hydraulic clamping device 10 of the first embodiment, since the cylindrical member 30 is fixed to the main body 12 not by press-fitting or brazing but by bonding with the adhesive of the adhesive layer 32, no stress from press-fitting remains on the cylindrical member 30. As a result, the concentricity, cylindricity, and roundness of the cylindrical member 30 are improved, and clamping with higher precision can be performed.

[0087] The cylindrical member 30 side of the working fluid chamber 40 is defined by a recessed portion (bored portion) 30D formed on the inner peripheral surface 30A of the cylindrical member 30, and is therefore thinner than the portion corresponding to the adhesive layer 32 and the O-ring 38 existing on the outside in the axial direction thereof. As a result, the diameter expansion deformation of the cylindrical member 30 caused by the pressure increase of the working oil in the working fluid chamber 40 is concentrated on the thin-walled portion caused by the recessed portion 30D.

[0088] Thus, stress caused by the diameter expansion deformation of the cylindrical member 30 is unlikely to act on the adhesive layer 32 and the O-ring 38 , and the bonding strength between the main body 12 and the cylindrical member 30 by the adhesive layer 32 and the liquid-tightness of the working fluid chamber 40 can be reduced.

[0089] The shoulder portion 42 functions as an adhesive stopper that prevents the adhesive of the adhesive layer 32 from invading the portion where the O-ring 38 is disposed, thereby suppressing the adhesive from adhering to the O-ring 38. Therefore, even if an adhesive is used, the elasticity of the O-ring 38 can be suppressed from being hindered by the adhesive that adheres to the O-ring 38 and hardens, thereby suppressing a reduction in the sealing performance. Thus, the liquid tightness of the working fluid chamber 40 can be stably ensured.

[0090] In addition, the shoulder portion 42 maintains the gap between the cylindrical member 30 at an optimum value over the entire circumference, thereby suppressing the circumferential variation of the thickness of the adhesive layer 32. As a result, the bonding strength between the main body 12 and the cylindrical member 30 based on the adhesive layer 32 is stabilized. In addition, the shoulder portion 42 also functions as a guide portion when the cylindrical member 30 is inserted into the mandrel main portion 16, thereby improving assembly workability.

[0091] The main body 12 and the cylindrical member 30 may be made of iron-based metals, but the cylindrical member 30 is fixed to the main body 12 by bonding with the adhesive of the adhesive layer 32, so that the main body 12 and the cylindrical member 30 can be made of different types of materials.

[0092] For example, the main body 12 may be made of a metal such as an iron-based metal, and the cylindrical member 30 may be made of a fiber-reinforced plastic such as GFRP, CFRP, or KFRP, or an engineering plastic having a higher elastic modulus than the main body 12, or an iron-based metal or non-iron-based metal having a higher wear resistance than the main body 12. That is, the main body 12 and the cylindrical member 30 may be made of a different material such that the elastic modulus or wear resistance of the cylindrical member 30 is higher than that of the main body 12.

[0093] Thus, the performance of the cylindrical member 30 can be specialized in high expansion property and wear resistance, which is different from that of the main body 12 .

[0094] In particular, the main body 12 is made of metal such as iron-based metal, while the cylindrical part 30 is made of CFRP. This ensures the required strength of the main body 12 and the cylindrical part 30 respectively, while making the performance (physical properties) of the cylindrical part 30 specialized in having high expandability, which is different from that of the main body 12.

[0095] As a result, the amount of diameter expansion deformation of the cylindrical member 30 relative to the predetermined pressure increase of the working fluid chamber 40 increases, and the clamped member W1 can be reliably clamped. In addition, the cylindrical member 30 is easily deformed by diameter expansion relative to the pressure increase of the working fluid chamber 40, so that the pressure increase of the working fluid chamber 40 for obtaining the required clamping force only needs to be small, and the bonding strength between the main body 12 and the cylindrical member 30 based on the adhesive layer 32 only needs to be small.

[0096] Next, refer to Figure 2 Embodiment 2 of the hydraulic clamping device of the present invention will be described. Figure 2 In, with Figure 1 The corresponding parts are marked with Figure 1 The same reference numerals as in the figure are used and their descriptions are omitted.

[0097] In the second embodiment, a ring member 70 made of resin or rubber is provided along the side surface of the O-ring groove 36 on the opposite side to the working fluid chamber 40 when viewed in the axial direction. The ring member 70 has a portion protruding radially outward from the O-ring groove 36, and the clearance of the inner peripheral surface 30A of the cylindrical member 30 is smaller than the fitting clearance generated by the difference between the outer diameter OD1 of the outer peripheral surface 16A of the spindle main portion 16 and the inner diameter ID1 of the inner peripheral surface 30A of the cylindrical member 30 by the amount of the protrusion.

[0098] Thus, the ring member 70 functions as an adhesive blocking portion equivalent to the shoulder portion 42 of the first embodiment, and prevents the adhesive of the adhesive layer 32 from invading the portion where the O-ring 38 is disposed. Thus, it is possible to suppress the adhesive from adhering to the O-ring 38, and even if an adhesive is used, it is possible to suppress the elasticity of the O-ring 38 from being hindered by the adhesive that adheres to the O-ring 38 and hardens, thereby suppressing the reduction in sealing performance. Thus, the liquid tightness of the working liquid chamber 40 can be stably ensured.

[0099] The ring member 70 also functions as a backup ring that prevents the O-ring 38 from intruding into the fitting gap due to deformation caused by the hydraulic pressure of the working fluid chamber 40. This prevents the O-ring 38 from being deformed and deteriorating the sealing performance due to abnormal deformation.

[0100] The second embodiment is substantially the same as the first embodiment except for the portion related to the ring member 70 , and has the same functions and effects as those of the first embodiment.

[0101] Next, refer to Figure 3 Embodiment 3 of the hydraulic clamping device of the present invention will be described. Figure 3 In, with Figure 1 The corresponding parts are marked with Figure 1 The same reference numerals as in the figure are used and their descriptions are omitted.

[0102] In the third embodiment, the mandrel main portion 16 has an O-ring groove 72 in the outer peripheral surface 16A between each O-ring groove 36 and the corresponding adhesive layer 32 at the fitting portion with the cylindrical member 30. In each O-ring groove 72, an O-ring 74 made of elastic body is mounted.

[0103] Each O-ring 74 abuts against the inner circumferential surface 30A of the cylindrical member 30 in an elastically compressed manner, and functions as an adhesive blocking portion that prevents the adhesive of the adhesive layer 32 from invading the portion where the O-ring 38 is disposed. This can prevent the adhesive from adhering to the O-ring 38, and even if an adhesive is used, it can prevent the elasticity of the O-ring 38 from being hindered by the adhesive that adheres to the O-ring 38 and hardens, thereby preventing the sealing performance from being reduced. This can stably ensure the liquid tightness of the working liquid chamber 40.

[0104] The third embodiment is substantially the same as the first embodiment except for the portion concerning the O-ring 74 , and has the same operation and effect as the first embodiment.

[0105] Next, refer to Figure 4 Embodiment 4 of the hydraulic clamping device of the present invention will be described. Figure 4 In, with Figure 1 The corresponding parts are marked with Figure 1 The same reference numerals as in the figure are used and their descriptions are omitted.

[0106] In the fourth embodiment, the mandrel main portion 16 has an outer diameter OD3 larger than the outer peripheral surface 16A at each position outside the axial direction of each adhesive layer 32 at the fitting portion fitted with the cylindrical member 30, that is, has a shoulder portion 44 formed by expanding the diameter. That is, the shoulder portion 44 is formed at a position farther from the working fluid chamber 40 than the adhesive layer 32 in the axial direction.

[0107] The shoulder portion 44 maintains the gap between the mandrel main portion 16 and the cylindrical member 30 at an optimum value over the entire circumference, thereby suppressing the circumferential variation in the thickness of the adhesive layer 32. As a result, the bonding strength between the main body 12 and the cylindrical member 30 based on the adhesive layer 32 is stabilized. In addition, the shoulder portion 44 also functions as a guide portion when the cylindrical member 30 is inserted into the mandrel main portion 16, thereby improving assembly workability.

[0108] The fourth embodiment is substantially the same as the first embodiment except for the portion related to the shoulder portion 44 , and has the same functions and effects as those of the first embodiment.

[0109] Next, refer to Figure 5 Embodiment 5 of the hydraulic clamping device of the present invention will be described. Figure 5 In, with Figure 1 The corresponding parts are marked with Figure 1 The same reference numerals as in the figure are used and their descriptions are omitted.

[0110] The hydraulic clamping device 10 of the fifth embodiment has a pair of adhesive layers 32, 82 and adhesive grooves 34, 80 provided between the body 12 and the cylindrical member 30 at respective positions on the outside in the axial direction of the two O-rings 38 (pair of sealing members), 74. The adhesive layers 32, 82 are formed by applying and filling the adhesive grooves 34, 80, respectively.

[0111] The adhesive layer 32 and the adhesive groove (one adhesive groove) 34 on the flange portion 18 side of the working fluid chamber 40 are formed on the outer peripheral surface 16A of the spindle main portion 16 in the same manner as in Embodiment 1. When viewed in the axial direction, an adhesive groove (another adhesive groove) 80 and an adhesive layer 82 on the first shaft end portion 14 side of the working fluid chamber 40 are formed on the inner peripheral surface 30A of the cylindrical member 30 on the side opposite to the flange portion 18.

[0112] The assembly (insertion) of the cylindrical member 30 relative to the main body 12 is as follows: Figure 6 As shown, first, each adhesive groove 34 (see Figure 5 ) and each adhesive groove 80 of the cylindrical member 30 (refer to Figure 5 ) is coated and filled with an uncured liquid adhesive to form adhesive layers 32, 82. In addition, in each O-ring groove 36, 72 (refer to Figure 5 ) and O-rings 38 and 74 are installed in the housing.

[0113] Afterwards, the cylindrical component 30 is moved along the axial direction from the end face 14A side of the first shaft end portion 14 toward the flange portion 18 relative to the main body 12 until the end face 30C of the cylindrical component 30 abuts against the end face 18A of the flange portion 18, so that the inner peripheral surface 30A of the cylindrical component 30 is embedded in the outer peripheral surface 16A of the main shaft portion 16.

[0114] In this embodiment, the flange portion 18 acts as an anti-mock portion when assembling the cylindrical component 30 relative to the main body 12, and the assembly direction (insertion direction) of the cylindrical component 30 relative to the main body 12 is limited to the left direction in the figure from the end face 14A side of the first shaft end 14 toward the flange portion 18, and insertion from the reverse direction is prohibited.

[0115] In addition, when the assembly position of the cylindrical part 30 in the axial direction relative to the main body 12 is determined based on the use of other clamps, etc., the end face 30C of the cylindrical part 30 does not need to abut the end face 18A of the flange portion 18, and the flange portion 18 only serves as an anti-mock portion when assembling the cylindrical part 30 relative to the main body 12.

[0116] When the cylindrical member 30 is viewed in the moving direction relative to the main body 12 (left direction in the figure) when the main body 12 and the cylindrical member 30 are engaged, the adhesive groove 34 and the adhesive layer 32 (the adhesive groove 34 and the adhesive layer 32 on one side) on the flange portion 18 side are located in front of any O-ring 38, 74. The adhesive groove 34 is formed in the main body 12. The adhesive groove 34 is formed on the outer periphery of the main body 12. The adhesive layer 32 is provided in the main body 12 before the main body 12 and the cylindrical member 30 are engaged.

[0117] On the other hand, the adhesive groove 80 and the adhesive layer 82 (the other adhesive groove 80 and the adhesive layer 82) on the opposite side to the flange portion 18 are located on the rear side when viewed in the moving direction compared to any O-ring 38, 74. The adhesive groove 80 is formed on the inner periphery of the cylindrical member 30. The adhesive layer 82 is provided on the cylindrical member 30 before the main body 12 and the cylindrical member 30 are fitted.

[0118] In other words, when viewed in the moving direction of the cylindrical part 30 relative to the main body 12, the adhesive groove 34 and the adhesive layer 32, which are located at the front side (flange portion 18 side) of any O-ring 38, 74 installed on the main body 12, are formed on the main body 12 before the main body 12 and the cylindrical part 30 are engaged with each other, and when viewed in the moving direction, the adhesive groove 80 and the adhesive layer 82, which are located at the rear side (opposite side of the flange portion 18) of any O-ring 38, 74, are formed on the cylindrical part 30 before the main body 12 and the cylindrical part 30 are engaged with each other.

[0119] Only the adhesive layer 32 on the flange portion 18 side relative to the working fluid chamber 40 is formed on the outer peripheral surface 16A of the main shaft portion 16 (main body 12), and the adhesive layer 82 on the side opposite to the flange portion 18 relative to the working fluid chamber 40 is formed on the inner peripheral surface 30A of the cylindrical part 30. Therefore, during the assembly (insertion) of the above-mentioned cylindrical part 30 relative to the main body 12, the adhesive of the adhesive layer 82 will not contact any O-ring 38, 74.

[0120] Thus, during assembly, the adhesive does not adhere to the O-rings 38 and 74 , and the functions of the O-rings 38 and 74 are not impaired due to adhesion and hardening of the adhesive.

[0121] The fifth embodiment is substantially the same as the first embodiment except for the adhesive grooves 34 and 80 and the adhesive layers 32 and 82 , and has the same functions and effects as the first embodiment.

[0122] Next, refer to Figure 7 Embodiment 6 of the hydraulic clamping device of the present invention will be described. Figure 7 In, with Figure 5 The corresponding parts are marked with Figure 5 The same reference numerals as in the figure are used and their descriptions are omitted.

[0123] In the sixth embodiment, the flange portion 18 is omitted, and the second shaft end portion 20 forms an expanded diameter portion on the left side of the figure relative to the spindle main portion 16. The second shaft end portion 20 defines an annular end surface (shoulder surface) 20B of the second shaft end portion 20 that faces the annular end surface 30C of the cylindrical member 30 at the boundary portion with the spindle main portion 16.

[0124] In this embodiment, the second shaft end 20 acts as an anti-mock portion when assembling the cylindrical component 30 relative to the main body 12. Similar to embodiment 5, the assembly direction (insertion direction) of the cylindrical component 30 relative to the main body 12 is limited to the left direction in the figure from the end face 14A side of the first shaft end 14 toward the end face 20B of the second shaft end 20, and insertion from the reverse direction is prohibited.

[0125] In this embodiment, when viewed in the moving direction of the cylindrical part 30 relative to the main body 12, the adhesive groove 34 and the adhesive layer 32, which are located at the front side (the side of the second shaft end 20) than any O-ring 38, 74 installed on the main body 12, are formed on the main body 12 before the main body 12 and the cylindrical part 30 are engaged with each other, and when viewed in the moving direction, the adhesive groove 80 and the adhesive layer 82, which are located at the rear side (the opposite side of the second shaft end 20) than any O-ring 38, 74, are formed on the cylindrical part 30 before the main body 12 and the cylindrical part 30 are engaged with each other.

[0126] Thus, during assembly (insertion) of the cylindrical member 30 into the main body 12 , the adhesive of the adhesive layer 82 does not come into contact with any of the O-rings 38 , 74 , and the functions of the O-rings 38 , 74 are not impaired due to adhesion and hardening of the adhesive.

[0127] Next, refer to Figure 8 Embodiment 7 of the hydraulic clamping device of the present invention will be described. Figure 8 In, with Figure 1 The corresponding parts are marked with Figure 1 The same reference numerals as in the figure are used and their descriptions are omitted.

[0128] In the seventh embodiment, each adhesive groove 34 has a triangular cross section of the same shape defined by an inclined surface 34A and an annular upright surface 34B, wherein the inclined surface 34A is formed by a tapered surface that slopes downward toward the flange portion 18, i.e., the groove becomes deeper, and the upright surface 34B rises radially outward from the terminal end of the inclined surface 34A. The upright surface 34B of each adhesive groove 34 is arranged on the front side (in the direction of insertion of the cylindrical member 30 relative to the main body 12) compared to the inclined surface 34A. Figure 8 The left side is viewed in the figure), and the side surface of the flange portion 18 side of the adhesive groove 34 is entirely formed.

[0129] According to each adhesive groove 34, by making the side surface of the flange portion 18 side of each adhesive groove 34 a vertical surface 34B, compared with the case where the side surface is a gently inclined surface, it is possible to effectively prevent the adhesive filled in each adhesive groove 34 from overflowing out of the adhesive groove 34 when the cylindrical part 30 is inserted relative to the main body 12, and the adhesive is likely to remain in the adhesive groove 34.

[0130] This can reduce wasteful consumption of the adhesive and suppress adhesion of the adhesive outside the adhesive groove 34 to the O-rings 38 and 74 .

[0131] The seventh embodiment is substantially the same as the first embodiment except for the shape of the adhesive groove 34 , and has the same functions and effects as the first embodiment.

[0132] Next, refer to Fig. 9 Embodiment 8 of the hydraulic clamping device of the present invention is described. Fig. 9 In, with Figure 1 The corresponding parts are marked with Figure 1 The same reference numerals as in the figure are used and their descriptions are omitted.

[0133] In the eighth embodiment, an annular outward flange portion (second outward flange portion) 31 extending radially outward from the axial end of the flange portion 18 is formed on the cylindrical member 30. The outward flange portion 31 faces the flange portion (first outward flange portion) 18 of the main body 12. An annular adhesive groove 33 is formed on the surface of the flange portion 18 facing the outward flange portion 31. The adhesive groove 33 is filled with an adhesive, and the adhesive constitutes an additional adhesive layer 35 existing between the opposing surfaces of the flange portion 18 and the outward flange portion 31.

[0134] The adhesive layer 35 is an adhesive layer for bonding (adhering) the main body 12 and the cylindrical member 30 to each other, and is an adhesive layer equivalent to the adhesive layer 32 . By adding the adhesive layer 35 , the bonding strength of the cylindrical member 30 to the main body 12 is increased.

[0135] The eighth embodiment is substantially the same as the first embodiment except for the portion related to the additional adhesive layer 35 , and has the same functions and effects as those of the first embodiment.

[0136] Next, refer to Fig.10 Embodiment 9 of the hydraulic clamping device of the present invention will be described. Fig.10 In, with Figure 1 The corresponding parts are marked with Figure 1 The same reference numerals as in the figure are used and their descriptions are omitted.

[0137] In the ninth embodiment, the adhesive groove 34 includes a spiral groove surrounding the outer circumference of the mandrel main portion 16 and includes an adhesive layer 32 formed of an adhesive filling the spiral groove.

[0138] By providing the spiral adhesive layer 32 , the adhesive strength (shear strength) of the cylindrical member 30 with respect to the main body 12 in the axial direction as well as the circumferential direction is improved.

[0139] The ninth embodiment is substantially the same as the first embodiment except for the portion related to the adhesive groove 34 , and has the same functions and effects as the first embodiment.

[0140] Next, refer to Fig.11 A tenth embodiment of the hydraulic clamping device according to the present invention will be described.

[0141] The hydraulic clamp 100 is a chuck type clamp having a main body (first member) 102. The main body 102 has a cylindrical portion 104 and a flange portion 106 in order on the same axis along the axial direction. The flange portion 106 is formed as an outward flange portion having a larger diameter than the cylindrical portion 104 and expanding in the radial direction.

[0142] A thin-walled cylindrical member (second member) 110 is fixed to the inner periphery of the main body 102 via an adhesive layer 112. The cylindrical member 110 has an outer peripheral surface (second peripheral surface) 110A that fits with the inner peripheral surface (first peripheral surface) 102A of the main body 102, and an inner peripheral surface 110B that clamps the round rod-shaped clamped member W2. The details of the fixing (bonding) of the cylindrical member 110 to the main body 102 by the adhesive layer 112 will be described later.

[0143] A circumferential groove-shaped recess 110C is formed on the outer circumferential surface 110A of the cylindrical member 110. The recess 110C defines a working fluid chamber 120 having an annular cross-sectional shape between the body 102 and the cylindrical member 110. The working fluid chamber 120 has a predetermined length in the axial direction and extends over the entire circumference of the inner circumferential surface 102A of the body 102.

[0144] Each adhesive layer 112 is provided in pairs at intervals along the axial direction at the fitting portion where the inner circumferential surface 102A of the main body 102 and the outer circumferential surface 110A of the cylindrical member 110 fit together, and two adhesive layers 112 are provided on both sides of the working liquid chamber 120 separated from the axial end of the working liquid chamber 120 along the axial direction, and the main body 102 and the cylindrical member 110 are fixed to each other by bonding (adhering). The adhesive layer 112 is formed by an adhesive filled in an adhesive groove 114, and the adhesive groove 114 is formed by a circumferential groove formed on the outer circumferential surface 110A of the cylindrical member 110. As a preferred adhesive for forming the adhesive layer 112, there are two-component epoxy adhesives, anaerobic adhesives, etc.

[0145] The thickness of each adhesive layer 112 formed by the adhesive filled in each adhesive groove 114 is determined by a value of 1 / 2 of the value obtained by subtracting the outer diameter of the adhesive groove from the inner diameter of the inner peripheral surface 102A of the main body 102. The optimal thickness of each adhesive layer 112 is determined by the maximum shear strength, which is determined by the type of adhesive, etc. The optimal dimension of each adhesive layer 112 in the axial direction is determined by the inner diameter of the cylindrical member 110, etc.

[0146] In the fitting portion where the inner circumferential surface 102A of the main body 102 and the outer circumferential surface 110A of the cylindrical member 110 are fitted, an O-ring groove 116 formed by a circumferential groove is formed on the outer circumferential surface 110A of the cylindrical member 110 between each adhesive layer 112 and the corresponding axial end of the working liquid chamber 120. An O-ring 118 made of an elastomer constituting a sealing member is installed in each O-ring groove 116. Each O-ring 118 abuts against the inner circumferential surface 102A of the main body 102 in an elastically compressed manner to perform a liquid-tight seal of the working liquid chamber 120.

[0147] In other words, the hydraulic clamping device 100 has a sealing member composed of a pair of annular O-rings 118 disposed between the main body 102 and the cylindrical member 110 at each position outside the two ends in the axial direction of the working fluid chamber 120. Furthermore, in order to fix the cylindrical member 110 relative to the main body 102, the hydraulic clamping device 100 has a pair of adhesive layers 112 disposed between the main body 102 and the cylindrical member 110 at each position outside the axial direction than the two O-rings 118 (pair of sealing members).

[0148] The two O-rings 118 are located at positions separated from each other in the axial direction, and are in elastic compression contact with the inner circumferential surface 102A of the main body 102 across the entire circumference, thereby centering the cylindrical part 110 relative to the main body 102 and improving the concentricity of the main body 102 and the cylindrical part 110.

[0149] The cylindrical member 110 has an O-ring groove 122 in the outer peripheral surface 110A between each O-ring groove 116 and the corresponding adhesive layer 112 at the fitting portion with the main body 102. In each O-ring groove 122, an O-ring 124 made of an elastic body is mounted.

[0150] Each O-ring 124 is in elastic compression contact with the inner peripheral surface 102A of the main body 102, and functions as an adhesive blocking portion that prevents the adhesive of the adhesive layer 112 from invading the portion where the O-ring 118 is disposed. This can prevent the adhesive from adhering to the O-ring 118, and even if the adhesive is used, it can prevent the elasticity of the O-ring 118 from being hindered by the adhesive that adheres to the O-ring 118 and hardens, thereby preventing the sealing performance from being reduced. This can stably ensure the liquid tightness of the working liquid chamber 120.

[0151] The body 102 has a piston chamber 130 extending in the axial direction. The piston 132 is fitted in the piston chamber 130 so as to be movable in the axial direction. One end of the piston chamber 130 communicates with the working fluid chamber 120 via a passage 134 formed in the radial direction of the body 102 .

[0152] The chamber space on the passage 134 side of the piston chamber 130 partitioned by the piston 132 , the passage 134 , and the working fluid chamber 120 form a closed space, and working oil (working fluid) such as grease is sealed therein.

[0153] The main body 102 is formed with a threaded hole 136, which extends in the axial direction and communicates with the other end of the piston chamber 130, and opens at the end surface 104A of the main body 102. A working threaded member 138 with a hexagonal hole is screwed into the threaded hole 136. A steel ball 140 is arranged between the working threaded member 138 and the piston 132. The working threaded member 138 is screwed into the threaded hole 136 toward the piston chamber 130 side, and the screwing is transmitted to the piston 132 via the steel ball 140.

[0154] Thus, a pressurizing structure is formed, and by screwing in the working screw member 138, the piston 132 is moved toward the passage 134 side (at Fig.11 The hydraulic clamp 100 moves (left side as viewed in the figure), thereby pressurizing the working oil in the working fluid chamber 120, and the cylindrical member 110 is deformed to reduce its diameter radially inward by radial elastic deformation due to the pressurization. As a result, the clamped member W2 is clamped on the inner circumferential surface 110B of the cylindrical member 110 based on the reduced diameter deformation of the cylindrical member 110. In more detail, the inner circumferential surface 110B of the cylindrical member 110 is closely attached to the outer circumferential surface of the clamped member W2 by the reduced diameter deformation of the cylindrical member 110, so that the clamped member W2 is fixed (clamped) to the hydraulic clamp 100.

[0155] In this way, the hydraulic clamping device 100 according to the tenth embodiment clamps the round bar-shaped clamped member W2 in a centered state (concentric state).

[0156] In the hydraulic clamping device 100 of the tenth embodiment, since the cylindrical member 110 is fixed to the main body 102 not by press-fitting but by bonding with the adhesive of the adhesive layer 112, no stress from the press-fitting remains on the cylindrical member 110. Thus, it is possible to avoid reduction in the concentricity, cylindricity, and roundness of the cylindrical member 110, and high-precision clamping can be performed.

[0157] The working fluid chamber 120 is defined by a recessed portion 110C formed on the outer peripheral surface 110A of the cylindrical component 110 and is therefore thinner than portions corresponding to the adhesive layer 112, O-rings 118, and 124 existing on the outside in the axial direction thereof. Therefore, the diameter reduction deformation of the cylindrical component 110 caused by the pressure increase of the working oil in the working fluid chamber 120 is concentrated on the thin-walled portion caused by the recessed portion 110C.

[0158] Therefore, the stress caused by the expansion and contraction deformation of the cylindrical part 110 is unlikely to act on the adhesive layer 112 and the O-ring 118, and the bonding strength between the main body 102 and the cylindrical part 110 based on the adhesive layer 112 and the liquid-tightness strength of the working liquid chamber 120 based on the O-ring 118 can be relatively small.

[0159] In this embodiment, the main body 102 and the cylindrical part 110 can also be made of iron-based metal, but the fixation of the cylindrical part 110 relative to the main body 102 is performed by bonding with the adhesive of the adhesive layer 112, so that the main body 102 and the cylindrical part 110 can be made of different types of materials.

[0160] Next, refer to Fig.12 Embodiment 11 of the hydraulic clamping device of the present invention is described. Fig.12 In, with Fig.11 The corresponding parts are marked with Fig.11 The same reference numerals as in the figure are used and their descriptions are omitted.

[0161] The hydraulic clamping device 100 of the eleventh embodiment has adhesive layers 112, 144 and adhesive grooves 114, 142 provided between the main body 102 and the cylindrical member 110 at respective positions on the outside in the axial direction of the two O-rings 118 (pair of sealing members) and 124. The adhesive layers 112, 144 are formed by applying and filling the adhesive grooves 114, 142, respectively.

[0162] The hydraulic clamping device 100 of embodiment 11 also has an inward flange portion (reduced diameter portion) 108 provided at the axial end on the flange portion 106 side of the main body 102. The inward flange portion 108 protrudes in an annular shape radially inward from the axial end of the main body 102, has an inner diameter smaller than the inner diameter of the inner peripheral surface 102A, and constitutes a part of the main body 102.

[0163] The end face 108A on the right side of the figure of the inward flange portion 108 constitutes a stop surface that uniquely determines the assembly position of the cylindrical component 110 relative to the axial direction of the main body 102 through the abutment with the end face 110D of the cylindrical component 110, and constitutes an anti-middle portion that limits the assembly direction (insertion direction) of the cylindrical component 110 relative to the main body 102 to the left direction in the figure from the end face 104A side of the cylindrical portion 104 toward the inward flange portion 108, and prohibits insertion from the reverse direction.

[0164] Furthermore, when the axial assembly position of the cylindrical member 110 relative to the main body 102 is determined by using another jig or the like, the end surface 110D of the cylindrical member 110 does not need to abut against the end surface 108A of the inward flange portion 108 .

[0165] When the main body 102 and the cylindrical member 110 are engaged with each other, when the cylindrical member 110 is viewed in the moving direction relative to the main body 102 (leftward in the figure), the adhesive groove 142 and the adhesive layer 144 (the adhesive groove 142 and the adhesive layer 144 on one side) on the inner flange portion 108 side are located in front of any O-ring 118, 124. The adhesive groove 142 is formed on the inner periphery of the main body 102. The adhesive layer 144 is provided on the main body 102 before the main body 102 and the cylindrical member 110 are engaged with each other.

[0166] On the other hand, the adhesive groove 114 and the adhesive layer 112 (the other adhesive groove 114 and the adhesive layer 112) on the opposite side to the inner flange portion 108 are located at the rear side when viewed in the moving direction compared to any O-ring 118, 124. The adhesive groove 114 is formed on the outer periphery of the cylindrical member 110. The adhesive layer 112 is provided on the cylindrical member 110 before the main body 102 and the cylindrical member 110 are fitted.

[0167] In other words, when viewed in the moving direction of the cylindrical part 110 relative to the main body 102, the adhesive groove 142 and the adhesive layer 144, which are located at the front side (toward the inner flange portion 108 side) of any O-ring 118, 124 installed on the main body 102, are formed in the main body 102 before the main body 102 and the cylindrical part 110 are engaged with each other, and when viewed in the moving direction, the adhesive groove 114 and the adhesive layer 112, which are located at the rear side (on the opposite side of the inner flange portion 108) of any O-ring 118, 124, are formed in the cylindrical part 110 before the main body 102 and the cylindrical part 110 are engaged with each other.

[0168] Only the adhesive layer 112 on the opposite side of the inner flange portion 108 than the working liquid chamber 120 is formed on the outer peripheral surface 110A of the cylindrical part 110, and the adhesive layer 144 on the inner flange portion 108 side than the working liquid chamber 120 is formed on the inner peripheral surface 102A of the main body 102. Therefore, during the assembly (insertion) of the above-mentioned cylindrical part 110 relative to the main body 102, the adhesive of the adhesive layer 112 will not contact any O-ring 118, 124.

[0169] Thus, the adhesive does not adhere to the O-rings 118 and 124 during assembly, and the functions of the O-rings 118 and 124 are not impaired due to adhesion and hardening of the adhesive.

[0170] Although preferred embodiments of the present invention have been described above, those skilled in the art can easily understand that the present invention is not limited to such embodiments and can be appropriately modified within the scope of the present invention.

[0171] In any embodiment, two adhesive layers 32, 82, 112, 144 are provided on both sides of the axial direction of the working liquid chamber 40, 120, but these adhesive layers 32, 82, 112, 144 may be provided one on each side of the axial direction of the working liquid chamber 40, 120, or may be provided in a plurality of two or more. The adhesive grooves 34, 80, 114, 142 are not essential, and the adhesive layers 32, 82, 112, 144 may be formed in the fitting gap between the outer peripheral surface 16A of the spindle main portion 16 and the inner peripheral surface 30A of the cylindrical member 30, or in the fitting gap between the inner peripheral surface 102A of the body 102 and the outer peripheral surface 110A of the cylindrical member 110. Fig.13 An embodiment in which the adhesive layer 32 is formed in the fitting gap between the outer peripheral surface 16A of the mandrel main portion 16 and the inner peripheral surface 30A of the cylindrical member 30 is shown.

[0172] The first shaft end 14, the main spindle portion 16, the flange portion 18 and the second shaft end 20 may not necessarily be located on the same axis, and the first shaft end 14 and the second shaft end 20 may not have the same outer diameter. In addition, the main spindle portion 16 may not have a larger outer diameter than the first shaft end 14 and the second shaft end 20.

[0173] The O-ring grooves 36 and 72 of the mandrel-type hydraulic clamping device 10 may be formed on the inner peripheral surface 30A of the cylindrical member 30, and the O-ring grooves 116 and 122 of the chuck-type hydraulic clamping device 100 may be formed on the inner peripheral surface 102A of the main body 102. In addition, one of the O-ring grooves 36, 72, 116, and 122 formed on both sides of the working fluid chamber 40 in the axial direction may be formed on the cylindrical member 30 and 110, and the other may be formed on the main body 12 and 102.

[0174] The cylindrical member 30, 110 may be assembled to the body 12, 102 by moving the body 12, 102 in the axial direction relative to the cylindrical member 30, 110. That is, the body 12, 102 and the cylindrical member 30, 110 may be fitted together by relative movement of the two in the axial direction.

[0175] The technical features of the above-mentioned embodiments may be combined with each other. The technical features of the mandrel-type hydraulic clamping device 10 shown in the first to ninth embodiments may be combined with the chuck-type hydraulic clamping device 100 of the tenth embodiment.

[0176] In addition, not all of the components described in the above embodiments are necessarily essential, and can be appropriately selected or discarded without departing from the gist of the present invention.

[0177] Description of symbols

[0178] 10: Hydraulic clamping device;

[0179] 12: Main body (first component);

[0180] 14: first shaft end;

[0181] 14A: end face;

[0182] 16: Main part of the mandrel;

[0183] 16A: outer peripheral surface (first peripheral surface);

[0184] 16B: concave part;

[0185] 18: flange portion (enlarged diameter portion, first outward flange portion);

[0186] 18A: end face;

[0187] 20: second shaft end portion (enlarged diameter portion);

[0188] 20A: end face;

[0189] 30: cylindrical component (second component);

[0190] 30A: inner circumference (second circumference);

[0191] 30B: outer peripheral surface;

[0192] 30C: end face;

[0193] 30D: concave part;

[0194] 31: outward flange portion (second outward flange portion);

[0195] 32: adhesive layer;

[0196] 33: adhesive slot;

[0197] 34: adhesive slot;

[0198] 34A: Bevel;

[0199] 34B: upright face;

[0200] 35: adhesive layer;

[0201] 36: O-ring groove;

[0202] 38: O-ring (sealing component);

[0203] 40: working liquid chamber;

[0204] 42: shoulder portion (adhesive blocking portion);

[0205] 44: shoulder;

[0206] 50: piston chamber;

[0207] 52: Piston;

[0208] 54: Passage;

[0209] 56: Passage;

[0210] 58: threaded hole;

[0211] 60: tool insertion hole;

[0212] 62: Working threaded parts;

[0213] 64: Steel ball;

[0214] 66: drilling holes;

[0215] 68: Steel ball;

[0216] 69: threaded plug;

[0217] 70: ring member (adhesive blocking portion);

[0218] 72: O-ring groove;

[0219] 74: O-ring (adhesive blocking portion);

[0220] 80: adhesive slot;

[0221] 82: adhesive layer;

[0222] 100: Hydraulic clamping device;

[0223] 102: main body (first component);

[0224] 102A: inner circumference (first circumference);

[0225] 104: Tubular part;

[0226] 104A: end face;

[0227] 106: flange portion;

[0228] 108: inward flange portion (reduced diameter portion);

[0229] 108A: end face;

[0230] 110: cylindrical component (second component);

[0231] 110A: outer peripheral surface (second peripheral surface);

[0232] 110B: inner circumference;

[0233] 110C: concave part;

[0234] 110D: end face;

[0235] 112: adhesive layer;

[0236] 114: adhesive slot;

[0237] 116: O-ring groove;

[0238] 118: O-ring;

[0239] 120: working liquid chamber;

[0240] 122: O-ring groove;

[0241] 124: O-ring (adhesive blocking portion);

[0242] 130: piston chamber;

[0243] 132: Piston;

[0244] 134: Passage;

[0245] 136: threaded hole;

[0246] 138: Working threaded parts;

[0247] 140: Steel ball;

[0248] 142: adhesive slot;

[0249] 144: adhesive layer;

[0250] A: center hole;

[0251] ID1: inner diameter;

[0252] OD1: outer diameter;

[0253] OD2: outer diameter;

[0254] OD3: outer diameter;

[0255] W1: clamped part;

[0256] W2: Clamped parts.

Claims

1. A hydraulic clamping device comprising: a first component having a first circular peripheral surface; and a second component having a second peripheral surface engaged with the first peripheral surface, A working fluid chamber is defined by a recessed portion provided on at least one of the first circumferential surface and the second circumferential surface, and the second member is elastically deformed in the radial direction by the pressure of the working fluid sealed in the working fluid chamber, thereby clamping the clamped member, wherein: The hydraulic clamping device comprises: annular sealing members, which are provided between the first member and the second member at positions outside both ends of the working fluid chamber in the axial direction, and form a pair sandwiching the working fluid chamber in the axial direction; Adhesive grooves formed of circumferential grooves, which are provided on both sides of the working liquid chamber in the axial direction on at least one of the first circumferential surface and the second circumferential surface, and form a pair sandwiching the working liquid chamber in the axial direction; as well as an adhesive layer formed of an adhesive filled in each of the pair of adhesive grooves, The adhesive layer is provided between the first component and the second component at respective positions on the outside of the pair of annular sealing components in the axial direction in order to fix the second component to the first component, and is located in a pair so as to sandwich the working fluid chamber and the pair of annular sealing components in the axial direction.

2. The hydraulic clamping device according to claim 1, wherein: One of the pair of adhesive grooves is provided in the first member, and the other is provided in the second member.

3. The hydraulic clamping device according to claim 1, wherein: The first component has an expanded diameter portion or a reduced diameter portion that defines an end face opposite to an end face of the second component, the adhesive groove on the expanded diameter portion or the reduced diameter portion side of the pair of adhesive grooves is arranged on the first component, and the adhesive groove on the opposite side of the expanded diameter portion or the reduced diameter portion of the pair of adhesive grooves is arranged on the second component.

4. The hydraulic clamping device according to any one of claims 1 to 3, wherein: The adhesive grooves each have a triangular cross-section defined by an inclined surface and a vertical surface.

5. The hydraulic clamping device according to any one of claims 1 to 3, wherein: The first component or the second component has a plurality of annular O-ring grooves formed on the first peripheral surface or the second peripheral surface, The sealing members each include an O-ring made of an elastic body and fitted into the O-ring groove.

6. The hydraulic clamping device according to any one of claims 1 to 3, wherein: An adhesive stopper portion is provided at an axial position between the sealing member and the corresponding adhesive layer on one side, wherein a gap between the first peripheral surface and the second peripheral surface is smaller than a gap at another axial position.

7. The hydraulic clamping device according to claim 6, wherein: The adhesive stoppers each include a shoulder portion formed on the first member by expanding the diameter.

8. The hydraulic clamping device according to claim 6, wherein: The adhesive blocking portion includes an O-ring made of an elastomer and provided on the first component or the second component.

9. The hydraulic clamping device according to any one of claims 1 to 3, wherein: The first component or the second component has a plurality of annular O-ring grooves formed on the first peripheral surface or the second peripheral surface, The sealing components each include an O-ring made of an elastic body and engaged with the O-ring groove. An adhesive stopper portion is provided at an axial position between the sealing member and the adhesive layer, wherein the gap between the first peripheral surface and the second peripheral surface is smaller than the gap at other axial positions. The adhesive stoppers each include a ring member provided along a side surface of the O-ring groove on the opposite side to the working fluid chamber when viewed in the axial direction and having a portion protruding in a radial direction from the O-ring groove.

10. The hydraulic clamping device according to any one of claims 1 to 3, wherein: The first member includes a shoulder portion formed by expanding the diameter at a position farther from the working fluid chamber than the pair of adhesive layers in the axial direction.

11. The hydraulic clamping device according to any one of claims 1 to 3, wherein: The first component and the second component are made of different kinds of materials.

12. The hydraulic clamping device according to claim 11, wherein: The first member is made of metal, and the second member is made of fiber-reinforced plastic having a higher elastic modulus than the metal constituting the first member.

13. The hydraulic clamping device according to any one of claims 1 to 3, wherein: The first component includes a rod-shaped portion, the first circumferential surface is the outer circumferential surface of the rod-shaped portion, and the second component includes a cylindrical portion, the second circumferential surface is the inner circumferential surface of the cylindrical portion. The cylindrical portion is deformed to expand in diameter by the pressure of the working fluid, thereby clamping the clamped component on the outer circumferential surface of the cylindrical portion.

14. The hydraulic clamping device according to claim 13, wherein: The first component includes a first outward flange portion, and the second component includes a second outward flange portion opposite to the first outward flange portion. An additional adhesive layer is provided between the mutually opposing surfaces of the first outward flange portion and the second outward flange portion.

15. The hydraulic clamping device according to any one of claims 1 to 3, wherein: The first component includes an opening extending in the axial direction, the first circumferential surface is the inner circumferential surface of the opening, and the second component includes a cylindrical portion, the second circumferential surface is the outer circumferential surface of the cylindrical portion, and the cylindrical portion is deformed by the pressure of the working fluid to clamp the clamped component on the inner circumferential surface of the cylindrical portion.

16. The hydraulic clamping device according to any one of claims 1 to 3, wherein: The hydraulic clamping device also has: a piston chamber formed in the first member and communicating with the working fluid chamber; a threaded hole formed in the first member and communicating with the piston chamber; a piston movably disposed in the piston chamber; and a working threaded component, which is screwed into the threaded hole, The hydraulic clamping device includes a pressurizing structure that pressurizes the working fluid in the working fluid chamber by moving the piston in the piston chamber as the working screw member is screwed in.

17. A method for manufacturing a hydraulic clamping device, which is a method for manufacturing a hydraulic clamping device according to any one of claims 1 to 16, wherein: The first component and the second component are fitted together by relatively moving the first component and the second component in the axial direction. Among the paired adhesive layers, the adhesive layer located at a position further forward than any of the sealing components when viewed in the moving direction of the second component relative to the first component is formed on the first component before the first component and the second component are fitted together, and the adhesive layer located at a position further rearward than any of the sealing components when viewed in the moving direction is formed on the second component before the fitting together.

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