JP6514914B2 - Non-excitation operating ball joint - Google Patents

Description

  The present invention relates to a non-excitation operating ball joint in which the holding state of a ball can be changed by the magnetic attraction of an electromagnetic coil and the spring force of a spring member.

  As a conventional non-excitation operation ball joint of this type, for example, there is one described in Patent Document 1. The non-excitation operating ball joint disclosed in Patent Document 1 connects two components of an articulated mechanism. This non-excitation operating ball joint has a sphere provided at one end of the shaft which is one of the constituent members, a housing which is the other constituent member, and an electromagnetic pressing mechanism which selectively presses the sphere on the housing. doing.

The spherical body is accommodated in a pressure receiving portion provided on one end side of the housing. The pressure receiving portion is formed to cover one side in the radial direction of the sphere. The pressure receiving portion is formed with a concave surface on which a part of the sphere is fitted. An electromagnetic pressing mechanism is provided on the other end side of the housing.
The electromagnetic pressing mechanism is disposed on the inside of the compression coil spring, a movable member opposed to a part on the other side of the sphere in the radial direction, a compression coil spring biasing the movable member toward the sphere, and the compression coil spring. Iron alloy rings and electromagnetic coils. The movable member is formed with a disk-shaped armature portion receiving magnetic attraction force and spring force of the spring member, and a pressing portion opposed to a part on the other side of the sphere in the radial direction. The pressing portion is formed with a concave surface on which a part of the sphere is fitted. The movable member is movably supported in the above-described radial direction in the housing.
The iron alloy ring and the electromagnetic coil are fixed to the housing.

  In this electromagnetic pressing mechanism, by exciting the electromagnetic coil, the armature portion of the movable member is magnetically attracted to the iron alloy ring against the spring force of the compression coil spring, and the sphere is rotatable relative to the housing Become. In this state, the other component can be moved relative to one component of the articulated mechanism.

  On the other hand, when the power supply to the electromagnetic coil is cut off, the movable member is pressed against the sphere by the spring force of the compression coil spring, and the sphere is caught by the movable member and the pressure receiving portion of the housing. By pressing the movable member against the sphere in this manner, the sphere is fixed to the housing, and the other component is fixed to one component of the articulated mechanism.

U.S. Patent No. 6,371,425

  The non-excitation operating ball joint disclosed in Patent Document 1 has a problem that the movable member becomes large in the moving direction. The reason is that the pressure receiving portion of the housing, the spherical body, the movable member, the iron alloy ring and the electromagnetic coil are arranged in a line. When such a non-excitation operating ball joint is used as a ball joint capable of holding the joint of the arm stationary and releasing the stationary holding in an industrial robot or the like, the joint becomes large in size.

  The present invention has been made to solve such problems, and it is an object of the present invention to provide a non-excitation operating ball joint which is compact in the moving direction of the magnetically attracted movable member.

In order to achieve this object, the non-excitation operating ball joint according to the present invention comprises a ball provided at one end of a shaft member for connecting parts, and a fixing member facing the ball from one side in the radial direction; A field core disposed on the other side in the radial direction with respect to the sphere in a state in which relative movement with the fixing member is restricted, a field core having a magnetic pole surface formed at one end adjacent to the sphere; A movable member having an electromagnetic coil, an end face magnetically attracted to the magnetic pole surface by magnetism, and movable in the radial direction at a position facing the spherical body from the other side in the radial direction; A spring member for urging the member toward the fixing member, the fixing member being formed in an annular shape having the radial direction as an axial direction, and a plate that receives a spring force of the spring member, and The circumference of the sphere And a first spherical body holding member made of a nonmagnetic material having a concave curved surface in contact with the movable member, the movable member is formed in an annular shape with the radial direction as an axial direction, and an armature constituting the end face; And a second spherical body holding member made of a nonmagnetic material and having a concave surface in contact with the circumferential surface of the spherical body, and the spherical body is partially inserted into the hollow portion of the fixed member and the hollow portion of the movable member. The fixed member and the movable member are held between the fixed member and the movable member so as to protrude from the fixed member to the opposite side to the movable member.

In the non-excitation operating ball joint according to the present invention, a ball provided at one end of a shaft member for connecting parts, a fixing member facing the ball from one side in the radial direction, and the fixing member A field core disposed on the other side in the radial direction with respect to the sphere in a state in which relative movement is restricted, a field core having a pole face formed at one end close to the sphere, and an electromagnetic coil provided in the field core; A movable member having an end face magnetically attracted to the magnetic pole surface, the movable member being movably disposed in the radial direction at a position facing the spherical body from the other side in the radial direction; And the fixing member is formed in an annular shape having the radial direction as an axial direction, and a plate which receives a spring force of the spring member, and a circumferential surface of the sphere. Contact concave surface And a first ball holding member made of non-magnetic material having,
The movable member includes an armature constituting the end face, and a non-magnetic second sphere holding member having a concave surface in contact with the circumferential surface of the sphere.
The spherical body is held by being held between the fixed member and the movable member in a state where a part of the sphere is inserted into the hollow portion of the fixed member and protrudes from the fixed member to the opposite side to the movable member. The core has a recess opening toward the movable member at a location intersecting the imaginary line extending through the center of the sphere and the radial line;
The spring member may be accommodated in the recess.

  According to the present invention, in the non-excitation operating ball joint, the first spherical body holding member and the second spherical body holding member are made of a synthetic resin as a material and are molded into a predetermined shape using a mold. It is also good.

  In the non-excitation operation ball joint according to the present invention, the first spherical body holding member and the second spherical body holding member have a cylinder whose axial direction is the radial direction, and the first spherical body holding member and The portion of the second spherical body holding member in contact with the spherical body is formed on the inner peripheral portion of the cylinder, and at least the fixed member of the fixed member and the movable member includes a reinforcing member fitted with the cylinder. It may be

  According to the present invention, the fixed member is disposed closer to the movable member than the end edge of the sphere in the direction in which the movable member is moved by the magnetic force or the spring force of the spring member. For this reason, as compared with the non-excitation operation ball joint described in Patent Document 1, it is possible to provide the non-excitation operation ball joint which is compact in the moving direction of the movable member.

1 is an exploded perspective view of a non-excitation operating ball joint according to the present invention. It is a front view of a non-excitation action | operation ball joint. FIG. 3 is a cross-sectional view of the main part in FIG. It is a front view of a field core. It is a sectional view of a field core, a part of electromagnetic coil, and a spring member. The broken position in FIG. 5 is a position shown by a VV line in FIG. It is a sectional view of a field core, a part of electromagnetic coil, and O ring. The broken position in FIG. 6 is a position shown by the VI-VI line in FIG. It is a figure which shows a side plate and a reinforcement board, FIG. 7 (A) is the sectional view on the AA line in FIG. 7 (B), FIG. 7 (B) is a front view of a side plate and a reinforcement board. FIG. 8A is a cross-sectional view taken along the line A-A in FIG. 8B, and FIG. 8B is a front view of the first ball holding member. Fig. 9 (A) is a sectional view taken along the line A-A in Fig. 9 (B), and Fig. 9 (B) is a front view of the armature. FIG. 10A is a cross-sectional view taken along the line A-A in FIG. 10B, and FIG. 10B is a front view of the second sphere holding member. FIG. 6 is a cross-sectional view of a non-excitation operating ball joint according to another embodiment.

First Embodiment
Hereinafter, an embodiment of a non-excitation operating ball joint according to the present invention will be described in detail with reference to FIGS.
The non-excitation operating ball joint 1 shown in FIG. 1 can be used, for example, to connect two arms of an articulated robot (not shown). The field core 2 located at the upper left in FIG. 1 is attached to one of the two arms.

The other arm is attached via the shaft member 4 to the sphere 3 located at the center of FIG. The shaft member 4 is for connecting other parts including the arm described above, and is fixed to the sphere 3 in a radially extending state of the sphere 3. The sphere 3 and the shaft member 4 according to this embodiment are each formed of stainless steel.
In this embodiment, for convenience, the direction from the field core 2 to the sphere 3 is referred to as the front, and the direction opposite to the front is referred to as the rear.

  The field core 2 constitutes a so-called clasper type electromagnet, and is formed in an annular shape by low carbon steel for machine structure. The field core 2 is formed with an annular groove 5 (see FIGS. 3 and 4) that opens toward one of the axial directions (forward in this embodiment). An annular electromagnetic coil 6 is accommodated in the annular groove 5. The electromagnetic coil 6 is formed by winding a wire (not shown) around the coil bobbin 7 as shown in FIG.

One end face of the field core 2 where the annular groove 5 is open is located on the outer pole face 11 located radially outward of the annular groove 5 and radially inward of the annular groove 5 as shown in FIG. It is constituted by the inner pole face 12. The pole faces 11 and 12 are formed at one end of the field core 2 close to the above-described sphere 3.
A plurality of four types of holes 13 to 16 are formed in the outer magnetic pole surface 11. These four types of holes 13 to 16 are three holes 13 for mounting screw insertion, three holes 14 for fixing the side plate, three holes 15 for coil spring insertion, and O ring fitting There are three holes 16. Three holes of the same type among the holes 13 to 16 are formed at positions where the field core 2 is equally divided into three in the circumferential direction. Further, these twelve holes 13 to 16 are formed in a line at equal intervals in the circumferential direction of the field core 2.

The mounting screw insertion hole 13 is a through hole which penetrates the field core 2 in the axial direction, as shown in FIG. Although not shown, the holes 13 are passed through bolts for attaching the field core 2 to, for example, an arm of an articulated robot.
The hole 14 for fixing the side plate is a screw hole, and as shown in FIG. 3, a bolt 19 for fixing a side plate 18 of the fixing member 17 described later is screwed. The bolt 19 passes through the collar 20 sandwiched between the side plate 18 and the field core 2 and the side plate 18 and is screwed into the hole 14 for fixing the side plate.

  The hole 15 for coil spring insertion is comprised by the large diameter hole 15a and the small diameter hole 15b, as shown in FIG. The large diameter hole 15 a is opened on the front surface (outer pole face 11) of the field core 2 and is formed deeper than the annular groove 5. A compression coil spring 21 is accommodated in the large diameter hole 15a. The compression coil spring 21 biases a movable member 22 described later in a direction away from the field core 2 in the axial direction of the field core 2. In this embodiment, the compression coil spring 21 constitutes a "spring member" in the present invention. The small diameter hole 15 b communicates the inside of the large diameter hole 15 a with the space behind the field core 2.

As shown in FIG. 6, the hole 16 for O-ring fitting is a non-through hole in which an O-ring 23 is fitted. When the movable member 22 described later is magnetically attracted to the field core 2 by O-ring 23, the O-ring 23 reduces the impact and makes the attraction noise smaller.
On the inner pole face 12 of the field core 2, as shown in FIG. 4, a plurality of caulking pieces 24 are formed to fix the coil bobbin 7 to the field core 2. These caulking pieces 24 are formed by plastically deforming the opening edge on the inner peripheral side of the annular groove 5 partially into the annular groove 5.

The fixing member 17 attached to the field core 2 by the bolt 19 is composed of three members as shown in FIGS. 2 and 3 and from the front side (one side in the radial direction of the ball 3) of the ball 3 Are facing each other. The three members constituting the fixing member 17 are the side plate 18, the first ball holding member 25 on the pressure receiving side, and the reinforcing plate 26.
The side plate 18 is formed in an annular plate shape by a hot-rolled mild steel plate. In this embodiment, the side plate 18 constitutes the “plate which receives the spring force of the spring member” in the invention described in claim 4.

  In the side plate 18, as shown in FIGS. 3 and 7, the first through hole 27 for passing the bolt 19 for fixing the side plate described above, the first spherical body holding member 25 and the reinforcing plate 26 are provided. A plurality of second through holes 28 (see FIG. 3) for fixing and notches 29 for passing bolts for field core attachment are formed.

  The first ball holding member 25 has a function of rotatably holding the ball 3 in cooperation with a movable member 22 described later and a function of holding the ball 3 in a stationary (locked) state. The first spherical body holding member 25 is formed in an annular shape having a flange 31 and a cylindrical body 32, as shown in FIG. The first ball holding member 25 is made of nonmagnetic material. The material forming the first sphere holding member 25 according to this embodiment is a polyacetal resin. That is, the first spherical body holding member 25 according to this embodiment is made of a synthetic resin, and is molded into a predetermined shape by injection molding using a mold.

The flange 31 is formed in an annular plate shape that can be overlapped with the side plate 18. As shown in FIG. 8B, the flange 31 is formed with a plurality of through holes 31a.
The cylindrical body 32 is formed with the above-mentioned radial direction (front-rear direction) of the spherical body 2 as the axial direction, and protrudes from the inner peripheral portion of the flange 31 in one axial direction (forward). In the assembled state of the fixing member 17 in which the first ball holding member 25 and the reinforcing plate 26 are attached to the side plate 18, the cylindrical body 32 has an inner peripheral portion of the side plate 18 and an inner peripheral portion of the reinforcing plate 26 described later. And fit with. Further, as shown in FIG. 3, the cylindrical body 32 penetrates the side plate 18 and the reinforcing plate 26 and protrudes forward from the reinforcing plate 26.

  A pressure receiving surface 33 for receiving a spring force acting on the ball 3 is formed on an inner peripheral portion of the cylindrical body 32. The pressure receiving surface 33 is formed of a concave surface on which the circumferential surface (spherical surface) of the sphere 3 is fitted. That is, the portion of the first ball holding member 25 in contact with the ball 3 is formed on the inner peripheral portion of the cylindrical body 32. The pressure receiving surface 33 of the cylindrical body 32 is formed in a shape in which a part of the spherical body 3 protrudes forward from the cylindrical body 32 in a state in which the spherical body 3 is fitted. The sphere 3 is thus sandwiched between the fixed member 17 and the movable member 22 described later in a state where a part is inserted into the hollow portion of the fixed member 17 and protrudes from the fixed member 17 to the opposite side to the movable member 22. It is held. The sphere 3 according to this embodiment is held in a state in which the portion supporting the shaft member 4 protrudes from the cylindrical body 32.

  In order to avoid interference with the shaft member 4 attached to the ball 3, the cylindrical body 32 is formed with a recess 34. The concave portion 34 is formed in a shape that extends in the circumferential direction by a predetermined length at two locations that bisect the cylinder 32 in the circumferential direction. In addition, the site | part (site | part which receives a spring force mainly) other than the recessed part 34 of the cylindrical body 32 can provide a reinforcement rib (not shown) in an outer surface, and can reinforce it.

The reinforcing plate 26 is formed in an annular plate shape by a synthetic resin. As shown in FIG. 7, a plurality of screw holes 35 are formed in the reinforcing plate 26. A fixing bolt 36 is screwed into the screw hole 35, as shown in FIG. The fixing bolt 36 is screwed to the screw hole 35 of the reinforcing plate 26 through the through hole 31 a of the flange 31 and the second through hole 28 of the side plate 18. That is, the reinforcing plate 26 is fixed to the side plate 18 together with the flange 31 of the first ball holding member 25 by a plurality of fixing bolts 36.
In this embodiment, the reinforcing plate 26 constitutes a "reinforcing member" in the invention according to the sixth aspect. The side plate 18 is sandwiched by the flange 31 and the reinforcing plate 26. In the reinforcing plate 26 according to this embodiment, as shown in FIG. 1 and FIG. 7, a clearance groove 37 which is continuous with the recess 34 of the first ball holding member 25 is formed. The length of the clearance groove 37 is equal to the length of the recess 34 of the cylinder 32 described above, as shown in FIG.

  The fixed member 17 according to this embodiment faces the ball 3 from the front side, and is fixed to the field core 2 by the bolt 19 in a state where the ball 3 is held between the fixed member 17 and the movable member 22. In other words, the field core 2 is disposed rearward of the sphere 3 (the other side in the radial direction of the sphere 3) in a state where relative movement with the fixing member 17 is restricted.

  As shown in FIG. 3, the movable member 22 is configured by two members, and is disposed at a position facing the sphere 3 and the rear side (the other side in the radial direction of the sphere 3). The movable member 22 according to this embodiment is formed in an annular shape whose axial direction is the above-described radial direction (front-rear direction). The sphere 3 is held by being held between the fixed member 17 and the movable member 22 in a state where a part of the sphere 3 is inserted into the hollow portion of the movable member 22.

The two members constituting the movable member 22 are an armature 41 and a second ball holding member 42 on the pressing side.
The armature 41 is formed in a ring plate shape by a hot-rolled steel plate. The end face of the armature 41 facing the field core 2 is magnetically attracted to the pole faces 11 and 12 of the field core 2 by exciting the electromagnetic coil 6. As shown in FIG. 9, three notches 43 for passing bolts for field core attachment and three guide grooves 44 for passing the above-described collar 20 are formed on the outer peripheral portion of the armature 41. ing.

The guide groove 44 is formed in a shape in which the collar 20 is slidably fitted. That is, the movable member 22 including the armature 41 moves between the field core 2 and the fixing member 17 only in the above-described radial direction (front-rear direction) by fitting the collars 20 into the plurality of guide grooves 44 respectively. It is arranged freely. The compression coil spring 21 and the O-ring 23 described above contact the portion between the three notches 43 of the armature 41 and the guide groove 44.
The armature 41 is provided with three screw holes 45 for attaching a second ball holding member 42 described later. The inner diameter of the armature 41 is equal to the inner diameter of the field core 2.

  The second ball holding member 42 has a function of rotatably holding the ball 3 in cooperation with the first ball holding member 25 and a function of holding the ball 3 in a stationary state. The second ball holding member 42 is made of nonmagnetic material. The material forming the second sphere holding member 42 according to this embodiment is a polyacetal resin. That is, the second spherical body holding member 42 is made of a synthetic resin and is formed into a predetermined shape by injection molding using a mold. This second spherical body holding member 42 is formed in an annular shape having a flange 46 and a cylinder 47 as shown in FIG. 10, and is provided on the front surface of the armature 41 by a plurality of mounting bolts 48 (see FIG. 3) It is attached. The mounting bolt 48 is screwed into the screw hole 45 of the armature 41.

The flange 46 is formed in an annular plate shape that can be stacked on the armature 41. As shown in FIG. 10, a plurality of through holes 49 are formed in the flange 46 for the attachment bolts 48 to pass through.
A reinforcing plate 50 can be attached to the flange 46 as shown by a two-dot chain line in FIG. The reinforcing plate 50 can be formed in an annular plate shape having a hole into which a cylinder 47 described later is fitted. The reinforcing plate 50 constitutes the "reinforcing member" in the invention according to claim 6.

The cylindrical body 47 is formed with the radial direction (front-rear direction) of the spherical body 3 described above as an axial direction, and protrudes forward from the inner peripheral portion of the flange 46. A pressing surface 51 for pressing the ball 3 is formed on the inner peripheral portion of the cylindrical body 47. The pressing surface 51 is formed of a concave surface on which the circumferential surface (spherical surface) of the sphere 3 is fitted. That is, the portion of the second spherical body holding member 42 in contact with the spherical body 3 is formed on the inner peripheral portion of the cylindrical body 47.
At the inner peripheral portion of the cylindrical body 47, a spigot portion 52 made of a cylinder fitted in the inner peripheral portion of the armature 41 is formed.

  As shown in FIG. 3, the second spherical body holding member 42 according to this embodiment is formed in such a shape that the rearmost end of the spherical body 3 reaches the open end (rear end) of the inlay portion 52. There is. That is, the sphere 3 is disposed at a position as close as possible to the field core 2 while satisfying the condition that it does not protrude from the armature 41 to the field core 2 side.

  The movable member 22 according to this embodiment is fixed to the field core 2 in a state where an air gap G having a predetermined width (see FIGS. 3, 5 and 6) is formed between the armature 41 and the field core 2. It is inserted between the members 17. The air gap G is generated by the armature 41 being pressed by the spring force of the compression coil spring 21 to press the ball 3 against the fixing member 17 in a state where the electromagnetic coil 6 is not excited. The air gap G is usually about 0.3 mm to 0.5 mm.

  In the non-excitation operation ball joint 1 configured as described above, when the electromagnetic coil 6 is in the non-excitation state, the sphere 3 is the first sphere holding member 25 of the fixed member 17 and the second sphere holding of the movable member 22. It is pinched by the spring force of the compression coil spring 21 with the member 42 and held stationary. In this state, the shaft member 4 can not be moved relative to the field core 2.

  When the magnetic flux Φ passes through the field core 2 and the armature 41 as shown by the two-dot chain line in FIG. 3, the armature 41 resists the spring force of the compression coil spring 21 and the field core 2 Is magnetically attracted to the By magnetically attracting the armature 41 to the field core 2 in this manner, the movable member 22 moves toward the field core 2 and the sphere 3 is released from the stationary state. At this time, by changing the magnitude of the excitation voltage of the electromagnetic coil 6, the strength of the holding force for holding the ball 3 can be adjusted. That is, the magnitude of the resistance when changing the angle of the shaft member 4 can be changed.

  The ball 3 of the non-excitation operation ball joint 1 according to this embodiment is partially inserted into the hollow portion of the fixed member 17 and protrudes from the fixed member 17 to the opposite side to the movable member 22. It is sandwiched and held by the movable member 22. The fixed member 17 is disposed at a position closer to the movable member 22 than the end edge (front end edge) of the sphere 3 in the direction in which the movable member 22 is moved by the magnetic force or the spring force of the compression coil spring 21. Therefore, according to this embodiment, it is possible to provide a compact non-excitation operating ball joint in the moving direction of the movable member 22 as compared to the non-excitation operating ball joint described in Patent Document 1.

The movable member 22 according to this embodiment is formed in an annular shape whose axial direction is the radial direction (front-rear direction) of the sphere 3 in which the fixed member 17 and the movable member 22 face the sphere 3. A part of the sphere 3 is inserted into the hollow portion of the movable member 22.
For this reason, in this embodiment, since the distance between the movable member 22 and the fixed member 17 can be further narrowed, a still more compact non-excitation operating ball joint can be provided.

The fixing member 17 according to this embodiment includes a side plate 18 receiving the spring force of the compression coil spring 21 and a first nonmagnetic spherical member holding member 25 having a concave surface contacting the circumferential surface of the spherical member 3. ing. The movable member 22 includes an armature 41 forming an end surface facing the pole faces 11 and 12 of the field core 2 and a second nonmagnetic spherical member holding member 42 having a concave surface in contact with the circumferential surface of the spherical member 3. Have.
According to this embodiment, the fixed member 17 and the movable member 22 need to have high rigidity, such as the side plate 18 and the armature 41, and the first and second spherical body holding members 25 whose rigidity may be relatively low. , 42, and can be formed separately. Since the side plate 18 and the armature 41 can be simplified in shape, even materials with high rigidity can be easily manufactured. In addition, since the first and second spherical body holding members 25 and 42 can be easily formed in a shape that conforms to the spherical body 3, the area of the portion in contact with the spherical body 3 can be increased. By this area becoming wide, the force holding the sphere 3 becomes strong.

  Furthermore, since the second ball holding member 42 is a nonmagnetic material, a leakage magnetic circuit is formed by passing the magnetic flux Φ of the electromagnetic coil 6 from the armature 41 through the second ball holding member 42 and the ball 3. You can prevent. For this reason, the fall of the suction | attraction force which attracts | sucks the armature 41 can be prevented.

The first and second ball holding members 25 and 42 according to this embodiment are made of synthetic resin and are molded into a predetermined shape using a mold.
For this reason, it is possible to form on the first and second spherical body holding members 25 and 42 a friction surface (a spherical holding surface consisting of the pressure receiving surface 33 and the pressing surface 51) formed of a concave surface having high processing accuracy. In this embodiment, since the first and second ball holding members 25 and 42 are formed of polyacetal resin, the first and second ball holding members 25 and 42 having high holding power of the balls 3 are obtained. be able to. The reason for this is that polyacetal resin is excellent in impact resistance and abrasion resistance, and deformation and distortion of the first and second ball holding members 25 and 42 are prevented.

  The first ball holding member 25 according to this embodiment is provided with a reinforcing member 26 in which the cylindrical body 32 is fitted. For this reason, since deformation and distortion of the cylindrical body 32 can be prevented, the holding power of the sphere 3 can be increased. When the reinforcing member 50 is provided on the movable member 22, the holding force of the ball 3 is further increased.

Second Embodiment
Another embodiment of the non-excitation operating ball joint according to the present invention will be described in detail with reference to FIG. In FIG. 11, the same or equivalent members as or to those described with reference to FIGS.
The field core 2 shown in FIG. 11 has an inner flange 61 facing the hole in the axial center. The inner flange 61 is provided on the rear surface of the field core 2 (the end surface opposite to the pole surfaces 11 and 12). For this reason, a recess 62 opening toward the movable member 22 is formed at the axial center of the field core 2. The recess 62 is formed at a portion intersecting the imaginary line L extending in the radial direction (front-rear direction) of the sphere 3 through the center of the sphere 3 in the field core 2.

  On the other hand, the armature 41 according to this embodiment is formed in a disk shape with no hole at the center. At the central portion of the armature 41, a bottomed cylindrical projecting portion 63 is formed. The projection 63 is inserted from the front into the recess 62 of the field core 2. Between the projecting portion 63 and the inner flange 61 of the field core 2, a compression coil spring 64 constituting a "spring member" in the present invention is accommodated in a compressed state. That is, the inner flange 61 and the projection 63 of the armature 41 substantially function as a spring seat.

  In the non-excitation operating ball joint 1 according to this embodiment, the spring member for biasing the armature 41 is only one compression coil spring 64 accommodated in the recess 62. In the outer peripheral portion of the field core 2 according to this embodiment, the hole 15 for accommodating the compression coil spring 21 shown in the first embodiment is not formed. Therefore, according to this embodiment, the area of the outer magnetic pole 11 is increased, so that the magnetic resistance of the magnetic circuit of the electromagnetic coil 6 can be reduced.

  In the non-excitation action ball joint 1 shown in the first embodiment and the second embodiment described above, in order to increase the holding force by the spring force of the compression coil springs 21 and 64, the ball 3 and the third This can be realized by increasing the coefficient of friction of the friction portion between the first and second ball holding members 25 and 42. In order to increase the coefficient of friction, for example, shot blasting is performed on at least one of the peripheral surface of the sphere 3 and the pressure receiving surface 33 and the pressing surface 51 of the first and second sphere holding members 25 and 42. Apply treatment to form irregularities on the surface. Alternatively, a friction material (not shown) may be coated on at least one of the peripheral surface of the sphere 3 and the ball pressure receiving surface 33 and the pressing surface 51, or the friction plate may be fixed. .

  DESCRIPTION OF SYMBOLS 1 ... non-excitation operation ball joint, 2 ... field core, 3 ... sphere, 4 ... shaft member, 6 ... electromagnetic coil, 11 ... outer magnetic pole surface, 12 ... inner magnetic pole surface, 17 ... fixing member, 18 ... side plate (Plate), 21, 64: Compression coil spring (spring member), 22: Movable member, 25: First spherical body holding member, 26, 50: Reinforcing plate (reinforcing member), 32: Tube body, 41: Armature, 42 second spherical body holding member 62 concave portion L imaginary line.

Claims (4)

A ball provided at one end of the shaft member for connecting parts;
A fixing member facing the sphere from one side in the radial direction;
A field core disposed on the other side in the radial direction from the sphere in a state in which relative movement with the fixing member is restricted, and a magnetic pole surface being formed at one end adjacent to the sphere;
An electromagnetic coil provided in the field core;
A movable member having an end face magnetically attracted to the magnetic pole surface and movably disposed in the radial direction at a position facing the spherical body from the other side in the radial direction;
A spring member for biasing the movable member toward the fixed member;
The fixing member is formed in an annular shape having the radial direction as an axial direction, and is made of a nonmagnetic material having a plate receiving a spring force of the spring member and a concave surface contacting the circumferential surface of the sphere. And a ball holding member of
The movable member is formed in an annular shape with the radial direction as an axial direction, and a non-magnetic second ball holding member made of a nonmagnetic material having an armature forming the end surface and a concave surface in contact with the peripheral surface of the ball Equipped with
The spheres, by the fixed member in a state of protruding on the opposite side of the hollow portion and said movable member from the fixed member is inserted into the hollow portion of the movable member partially said fixed member and said movable member A non-excitation operating ball joint characterized in that it is sandwiched and held. A ball provided at one end of the shaft member for connecting parts;
A fixing member facing the sphere from one side in the radial direction;
A field core disposed on the other side in the radial direction from the sphere in a state in which relative movement with the fixing member is restricted, and a magnetic pole surface being formed at one end adjacent to the sphere;
An electromagnetic coil provided in the field core;
A movable member having an end face magnetically attracted to the magnetic pole surface and movably disposed in the radial direction at a position facing the spherical body from the other side in the radial direction;
A spring member for biasing the movable member toward the fixed member;
The fixing member is formed in an annular shape having the radial direction as an axial direction, and is made of a nonmagnetic material having a plate receiving a spring force of the spring member and a concave surface contacting the circumferential surface of the sphere. And a ball holding member of
The movable member includes an armature constituting the end face, and a non-magnetic second sphere holding member having a concave surface in contact with the circumferential surface of the sphere.
The spherical body is held by being held between the fixed member and the movable member in a state where a part of the sphere is inserted into the hollow portion of the fixed member and protrudes from the fixed member to the opposite side to the movable member.
The field core has a recess opening toward the movable member at a location intersecting the imaginary line extending through the center of the sphere and the radial direction.
A non-excitation operating ball joint characterized in that the spring member is accommodated in the recess. In the non-excitation operating ball joint according to claim 1 or 2 ,
The first ball holding member and the second ball holding member are made of a synthetic resin and are molded into a predetermined shape using a mold. In the non-excitation operating ball joint according to any one of claims 1 to 3 ,
The first ball holding member and the second ball holding member have a cylinder whose axial direction is the radial direction,
The portions of the first ball holding member and the second ball holding member in contact with the ball are formed on the inner circumferential portion of the cylinder,
Among the fixed member and the movable member, at least the fixed member includes a reinforcing member with which the cylindrical body is fitted.

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