JP4638804B2 - Roller bearing cage mold - Google Patents

Description

  The present invention relates to a mold for forming a cage for holding a plurality of rollers in a roller bearing.

  A plurality of rollers disposed between the outer peripheral surface of the inner peripheral side member and the inner peripheral surface of the outer peripheral side member, and the rollers are rotatably held in the pocket, and rotate around the inner peripheral side member. 2. Description of the Related Art Roller bearings including a cage that is widely used are widely used. In roller bearings, it is indispensable to provide clearances between the pockets of the cage to allow the rollers to rotate. It is essential to provide a gap for allowing the cage to rotate between the peripheral surface and the outer peripheral surface of the inner peripheral member. Due to the presence of these gaps, it is inevitable that the rollers are inclined in the circumferential direction of the inner peripheral member, and the inclination angle in the circumferential direction of the roller axis with respect to the axis of the inner peripheral member is called a skew angle. If there is a skew angle, as the inner peripheral member and the outer peripheral member rotate relative to each other, the rollers move in the axial direction while rolling, and an axial force that is an axial force is applied to the cage. Forces opposite to each other in the axial direction are also applied to the inner peripheral member and the outer peripheral member. The direction of this axial force changes depending on whether the skew angle is positive or negative, and since the positive and negative skew angles change randomly, the direction of the axial force also changes randomly, and a device with roller bearings Cause vibration and noise.

Therefore, Patent Document 1 below describes that the skew angle is reduced to 1.5 / 1000 or less of the roller length by suppressing the inclination in the circumferential direction of the pocket, thereby reducing the vibration and noise of the roller bearing. ing.
In Patent Document 2, when the cage is injection-molded with a synthetic resin containing reinforcing fibers, a gate is provided at one end in the axial direction of the cage to increase the strength of the cage against stress concentration at the pocket corners. Is described.
Japanese Patent Laid-Open No. 11-344035 Japanese Patent Laid-Open No. 10-318265 JP-A-7-127645

  In view of the above circumstances, an object of the present invention is to obtain a mold capable of manufacturing a cage capable of reducing the vibration of a roller bearing by resin injection molding.

  The above problem is to hold a plurality of rollers arranged between the outer peripheral surface of the inner peripheral side member and the inner peripheral surface of the outer peripheral side member so as to be able to rotate in the pocket, and rotate around the inner peripheral member. In a mold for manufacturing a cage by resin injection molding, a gate for injecting molten resin into a cavity for molding the cage is opened in a cavity surface for molding one end surface in the axial direction of the cage The part where the gate is formed can be rotated relative to the other part of the mold around the center line of the cavity and fixed to the other part after adjusting the relative rotational position. It is solved by making it possible.

  According to this mold, the cage whose inner peripheral surface and outer peripheral surface are both tapered can be manufactured at a lower cost than when a tapered surface is formed by machining such as grinding or cutting. it can. In addition, since the part of the mold where the gate is formed can be rotated relative to the other part, it is possible to change which part of the cavity is to be opened to the part of the cavity. it can. For example, the gate can be arbitrarily changed from a state where the gate is opened at the center position of the portion forming the pocket of the cage to a state where the gate is opened at the center position of the pillar existing between the adjacent pockets. In this case, the relative rotation position between the gate and the cavity can be arbitrarily changed. As will be described in detail later in the section of the embodiment, the taper and roundness of the molded cage change according to the change in the relative rotational position of the gate and the cavity, and depending on what type of cage is desired to be obtained. Thus, the position of the gate can be arbitrarily changed.

Aspects of the Invention

  In the following, the invention that is claimed to be claimable in the present application (hereinafter referred to as “claimable invention”. The claimable invention is at least the “present invention” to the invention described in the claims. Some aspects of the present invention, including subordinate concept inventions of the present invention, superordinate concepts of the present invention, or inventions of different concepts) will be illustrated and described. As with the claims, each aspect is divided into sections, each section is numbered, and is described in a form that cites the numbers of other sections as necessary. This is for the purpose of facilitating the understanding of the claimable invention, and is not intended to limit the combinations of the constituent elements constituting the claimable invention to those described in the following sections. In other words, the claimable invention should be construed in consideration of the description accompanying each section, the description of the embodiments, etc., and as long as the interpretation is followed, another aspect is added to the form of each section. In addition, an aspect in which constituent elements are deleted from the aspect of each item can be an aspect of the claimable invention.

  The following items (1) to (5) correspond to claims 1 to 5, respectively.

(1) A plurality of rollers disposed between the outer peripheral surface of the inner peripheral side member and the inner peripheral surface of the outer peripheral side member are held in a pocket so as to be able to rotate, and rotate around the inner peripheral side member. A mold for producing the cage by resin injection molding,
A gate for injecting a molten resin into a cavity for molding the cage of the mold is formed in a state of opening one end surface in the axial direction of the cage to a cavity surface for molding, and the gate is formed. The part can be rotated relative to the other part of the mold around the center line of the cavity, and can be fixed to the other part after adjustment of the relative rotational position. Cage mold.
(2) The relative rotation between the part where the gate of the mold is formed and the other part corresponds to at least the center in the circumferential direction of the part where the gate forms the pocket of the cage in the cavity. The cage mold according to (1), which is possible between a relative rotational position opened at a position and a relative rotational position opened at the center in the circumferential direction of a pillar existing between pockets adjacent to each other. .
(3) The mold is
A gate forming member having a circular cross-sectional shape which is a portion where the gate is formed;
A mold member that holds the gate forming member rotatably about the central axis of the gate forming member;
The gate forming member and the die member are provided between the gate forming member and the die member and screwed to each other, and the gate forming member and the die are moved by the relative movement in the axial direction accompanying the relative rotation of both screw members The cage mold according to the item (1) or (2), including a screw type adjusting device for adjusting a relative rotational position with respect to the member.
According to the screw type adjusting device, fine adjustment of the relative rotational position of the gate forming member and the mold member can be easily performed.
(4) The screw adjusting device is
An arm having one end fixed to the gate forming member and the other end extended to a position facing the mold member;
A male screw member in which one end is rotatably supported by the mold member around a rotation axis parallel to the central axis of the gate forming member, and a male screw is formed on the other end;
The cage molding die according to item (3), including at least one nut that is screwed into the male screw portion and engages with the arm.
(5) A portion that is provided across the gate forming member and the mold member, and that changes with relative rotation of the gate forming member and the mold member, and a portion that molds the pocket of the cage of the cavity; The cage molding die according to any one of items (1) to (4), including a relative rotational position indicating device that indicates the relative rotational position.
Since the retainer column is formed between the pockets adjacent to each other, the relative rotational position indicating device indicates the relative rotational position between the gate and the portion forming the pocket of the cavity as described above. It can be considered to be a thing, or it can be considered to indicate a relative rotational position between the gate and the part for forming the column.

  Hereinafter, embodiments of the claimable invention will be described in detail with reference to the drawings. In addition to the following examples, the claimable invention can be practiced in various modifications based on the knowledge of those skilled in the art, including the aspects described in the above [Aspect of the Invention] section. .

First, a roller bearing provided with a cage to be manufactured using the mold of the present invention will be described.
FIG. 1 shows a brake actuator with a built-in hydraulic pump. The brake actuator 10 is a hydraulic pressure control unit of a hydraulic brake system for a vehicle, and includes an actuator block 12, a pump motor 14 (which is an electric motor) fixed to the block 12, an accumulator 16, and the like. ing. A hydraulic pump is incorporated in the block 12 together with an electromagnetic hydraulic valve and the like, and a fluid passage for brake fluid is formed in a state of connecting them. Further, the block 12 includes a master cylinder port 18 connected to the master cylinder, a reservoir port 20 connected to the reservoir, and a plurality of hole cylinder ports 22 connected to wheel cylinders provided on each of the four wheels. It has been. The hydraulic pump is incorporated in the upper half of the block 12 shown in the figure and is driven by a pump motor 14.

  FIG. 2 shows a cross-sectional view of the hydraulic pump 30. The hydraulic pump 30 includes a part of the housing 32 of the actuator block 12 as its own housing and includes two plunger pump portions 34 and an eccentric cam 36.

  The two plunger pump portions 34 mainly include a cylinder 40 fitted in a fitting hole 37 penetrating the housing 32 in the vertical direction in the figure and a plunger 42 fitted therein, and are provided on both sides of the eccentric cam 36. It has been. The cylinder 40 has a substantially bottomed cylindrical shape, and a rear end opposite to the opening side of the plunger hole 43 into which the plunger 42 is fitted is supported by a plug 44. A spring 46 is provided between the rear end portion of the plunger 42 and the bottom portion of the cylinder 40, and the plunger 42 is urged by the spring 46 so as to protrude from the cylinder 40. The plunger 42 is provided with a liquid passage 48 that connects the outer peripheral surface near the front end and the rear end, and the bottom of the cylinder 40 is provided with another liquid passage 50 that penetrates the bottom wall. Yes. A ball 52 as a valve element is disposed at the rear end of the plunger 42 so as to be seated in an opening of a liquid passage 48 as a valve seat, and another valve is disposed at the rear end of the cylinder 40. A ball 54 as a child is arranged in a state of being pressed by a spring 56 to an opening of a liquid passage 50 as a valve seat. The space in front of the cylinder 40 is a low-pressure fluid chamber filled with low-pressure brake fluid, and when the plunger 42 is reciprocated, the brake fluid in the low-pressure fluid chamber is pressurized and the fluid passages 48 and 50 are passed through. It passes through and is discharged into the space behind the cylinder 40. This space is a high-pressure liquid chamber, and is communicated with an electromagnetic hydraulic valve through a liquid passage.

  The eccentric cam 36 is mainly composed of the eccentric cam shaft 60. The eccentric cam shaft 60 is rotatably held in journal holes 61 and 62 at both ends in shaft holes formed in the housing 32 at right angles to the fitting holes 37 via two ball bearings 63 which are radial bearings. Yes. In the central part of the eccentric cam shaft 60 in the axial direction, an intermediate diameter part slightly thicker than the journal parts 61 and 62 which are small diameter parts and a large diameter part thicker than that are provided. The large-diameter portion is an eccentric shaft portion 64 that is eccentric with respect to the journal portions 61 and 62, and a ring 72 is rotatably provided on the outer periphery thereof via a needle bearing 66. The needle bearing 66 is a kind of roller bearing, and includes a cage 68 and a plurality of needles 70 held by the cage 68. It can be considered that the ring 72 is an outer race and the outer peripheral portion of the eccentric shaft portion 64 constitutes an inner race, and that the outer race and the inner race constitute a needle bearing 66 together with the cage 68 and the needle 70. It can also be considered that the inner race is not provided and the outer race (ring 72), the retainer 68 and the needle 70 constitute the needle bearing 66. Ring balancers 74 and 76 having an inner peripheral surface and an outer peripheral surface eccentric to each other are fitted to the two intermediate diameter portions of the eccentric cam shaft 60 so as not to rotate with respect to the eccentric cam shaft 60. The balancers 74 and 76 cancel the deviation of the center of gravity caused by the eccentric shaft portion 64, the needle bearing 66 and the ring 72, and play a role of balancing the eccentric cam shaft 60.

  The balancers 74 and 76 are sandwiched between the eccentric shaft portion 64 and the inner race of the ball bearing 63, and are not in contact with the outer race of the ball bearing 63. The balancers 74 and 76 are pressed and fixed to both end surfaces of the eccentric shaft portion 64 by inner races of the ball bearings 63 that are tightly fitted to the journal portions 61 and 62. Is slightly shorter than the eccentric shaft portion 64 and can freely rotate. A wave washer 78 is interposed between the outer race of one ball bearing 63 and the bottom surface of the shaft hole, while the outer race of the other ball bearing 63 is brought into contact with the oil seal 82 via a spacer 80. . The inner race of the ball bearing 63 is tightly fitted to the journal portions 61 and 62 as described above, but the outer race is loosely fitted to the housing 32. The components arranged in series in the axial direction from the wave washer 78 to the oil seal 82 are sandwiched between the bottom surface of the shaft hole and the support plate 84 of the pump motor 14. Directional movement is suppressed. The projecting end portion of the eccentric cam shaft 60 extending toward the pump motor 14 is a connecting portion 86, and is engaged with an engaging portion 88 provided at the tip of the output shaft of the motor 14, whereby the motor 14. Is transmitted to the eccentric cam shaft 60. Each plunger 42 of the two plunger pump parts 34 is engaged with the ring 72 at the tip thereof, and if the eccentric cam shaft 60 is rotated, the eccentric shaft part 64 is eccentrically rotated, and the plunger 42 is moved. Reciprocate.

  In the needle bearing 66, the direction of the axial force acting on the eccentric cam shaft 60, the retainer 68 and the ring 72 due to the skew of the needle 70 during operation of the hydraulic pump 30 is made constant. Yes. That is, the cage 68 and the ring 72 are always subjected to the axial force directed to the right in FIG. 1 with respect to the eccentric cam shaft 60. Specifically, as shown in an exaggerated manner in FIG. 2, the retainer 68 is an inner diameter guide type whose radial position is determined by fitting the inner peripheral surface thereof and the outer peripheral surface of the eccentric shaft portion 64. As shown exaggeratedly in FIG. 3, both the inner diameter and the outer diameter gradually increase from the right end toward the left end, and the eccentric shaft portion 64 is rotated counterclockwise as indicated by the arrow A. The needle 70 is tilted in the same direction by being tilted in the state shown in the figure. The needle 70 shown in FIG. 3 mainly receives the reaction force from the plunger pump unit 34 among the plurality of needles 70 held by the retainer 68, and the needle 70 has a ring 72 indicated by a two-dot chain line. The ring 72 is strongly sandwiched between the inner peripheral surface and the outer peripheral surface of the eccentric shaft portion 64, and in the direction indicated by the arrow B on the outer peripheral surface of the eccentric shaft portion 64 as the eccentric shaft portion 64 and the ring 72 rotate relative to each other. Rolls in the direction opposite to the arrow B. Actually, the eccentric shaft portion 64 rotates and the ring 72 does not rotate. However, for easy understanding, hereinafter, the eccentric shaft portion 64 does not rotate, and the eccentric shaft portion 64 is not rotated. The description will be made assuming that the ring 72 rotates clockwise.

When the ring 72 rotates in the direction opposite to the arrow A with respect to the eccentric shaft portion 64, the needle 70 held in the pocket 92 of the cage 68 applies a force in the direction of the arrow B to the inner surface of the pocket 92. , Trying to move the pocket 92 in that direction. On the other hand, the movement of the cage 68 is blocked by the eccentric shaft portion 64 at the right end thereof, so that the cage 68 is tilted in the direction of FIG. The contact point between the right end of the retainer 68 and the eccentric shaft portion 64 and the contact point between the needle 70 and the pocket inner surface are shifted in a direction perpendicular to the paper surface in FIG. Rotational moment acts. Further, since a frictional force acts between the inner peripheral surface of the retainer 68 and the outer peripheral surface of the eccentric shaft portion 64, strictly speaking, the retainer 68 is separated from the plunger pump portion 34 as shown in FIG. It does not contact the eccentric shaft portion 64 at a position that is 90 ° apart from the needle 70 that mainly receives the reaction force, but contacts at a position that is separated from the needle 70 by an angle smaller than 90 °. There is no change in tilting. With this inclination, the pocket 92 is also inclined at an angle α in a direction of turning clockwise in FIG.

  It is indispensable to provide a gap between the inner surface of the pocket 92 and the needle 70 in order to allow the needle 70 to rotate. Therefore, the needle 70 can freely tilt in the pocket 92. Conventionally, the pocket 92 has been prevented from tilting as much as possible with respect to the axis of the eccentric shaft portion 64 in the circumferential direction of the eccentric shaft portion 64. Therefore, if the needle 70 freely tilts in the pocket 92, the eccentric shaft portion 64 The sign of the skew angle, which is the inclination angle of the axis C of the needle 70 with respect to the axis D of the eccentric shaft portion 64 in the circumferential direction, becomes positive or negative. The axis C of the needle 70 is rotated clockwise or counterclockwise with respect to the axis D of the eccentric shaft portion 64 in FIG. On the other hand, in this example, during the operation of the hydraulic pump 30, the pocket 92 is inclined in the positive direction (with the clockwise direction being positive) with respect to the axis D of the eccentric shaft portion 64. Further, since this angle α is larger than the maximum value of the angle at which the needle 70 can rotate in the pocket 92, the inclination angle β of the axis C of the needle 70 with respect to the axis D of the eccentric shaft portion 64 is Even when 70 is rotated to the maximum in the counterclockwise direction (negative direction) in the pocket 92, it does not become negative.

  If the skew angle β of the needle 70 is kept positive, the needle 70 always rolls obliquely in the upper right direction on the outer peripheral surface of the eccentric shaft portion 64 in FIG. 3 as the ring 72 rotates with respect to the eccentric shaft portion 64. . As a result, the needle 70 and the ring 72 tend to move to the right with respect to the eccentric shaft portion 64, and the retainer 68 also receives a rightward force from the needle 70. Since the needle 70 can be freely tilted in the pocket 92, the magnitude of the skew angle may vary, but the sign is always positive and constant, whereby the shaft acting on the cage 68 and the ring 72 The directional force is always to the right.

  In this example, the rightward force of the retainer 68 and the ring 72 is transmitted to the eccentric cam shaft 60 through the balancer 76 and the inner race of the right ball bearing 63, and the retainer 68 and the ring 72. It is balanced with the reaction force of the rightward force. Thus, since a rightward force always acts on the cage 68 and the ring 72 and a leftward force always acts on the eccentric cam shaft 60, the direction of these forces may be rightward or leftward. Compared to the conventional case, the vibration in the axial direction of the eccentric cam shaft 60, balancers 74 and 76, ball bearing 63, etc. can be reduced, but it does not stop. This vibration is received on the one hand by the oil seal 82 via the ball and outer race of the right ball bearing 63 and the spacer 80, and on the other hand, the wave washer via the ball and outer race of the left ball bearing 63. 78.

The oil seal 82 is mainly composed of rubber, and there is a relationship shown in FIG. 4 between the elastic force generated by compression of the oil seal and the amount of compression. The relationship shown in FIG. 5 exists between the elastic force generated by the compression of the wave washer 78 and the amount of compression. The oil seal 82 has the property that the spring constant increases as the elastic force increases, while the wave washer 78 has the property that the spring constant decreases as the elastic force increases. The position of the eccentric cam 36 positioned by being sandwiched from both sides in the axial direction by the wave washer 78 is mainly determined by the oil seal 82, and the magnitude of the elastic force between the oil seal 82 and the wave washer 78 is mainly the wave washer 78. It will be decided by. In addition, as described above, the vibration damping coefficient of the rubber oil seal 82 that mainly positions the eccentric cam 36 in the axial direction is larger than that of the metal wave washer 78. Axial vibration is effectively damped. Therefore, the operation noise and vibration of the hydraulic pump 30 that have conventionally occurred due to the axial vibration of the eccentric cam 36 during operation of the hydraulic pump 30 are reduced.
In this example, the balancer 74, the right ball bearing 63, the spacer 80, and the oil seal 82 constitute a main movement limit defining portion, and the balancer 76, the left ball bearing 63, and the wave washer 78 constitute a secondary movement limit defining portion. It has been done.

  Moreover, the natural frequency of the axial vibration of the eccentric cam 36 determined based on the spring constants of the oil seal 82 and the wave washer 78 and the mass of the eccentric cam 36 is the natural vibration of the brake actuator 10 in a state of being attached to the vehicle body. Therefore, the brake actuator 10 and the portion of the vehicle body that holds the brake actuator 10 resonate with the primary or secondary vibration of the eccentric cam 36. From this point, the operation noise and vibration of the hydraulic pump 30 can be reduced.

  FIG. 6 shows another needle bearing which is a roller bearing. In this example, a roller 104 is rotatably held by a fixed support shaft 102 via a needle bearing 106. The needle bearing 106 is fitted to a plurality of needles 112, a retainer 114 that rotates around the support shaft 102, and the outer periphery of the needle 112 and the retainer 114. The outer race 116 is provided, and the roller 104 is fitted to the outer peripheral side of the outer race 116. Thrust bearings 122 and 124 (which may be sliding bearings or rolling bearings) are disposed on both sides of the cage 114 and the outer race 116, and the axial force acting on one of the thrust bearings 122 is an oil seal 126 and a washer. 128 and the C-shaped retaining ring 132 can be received by the support shaft 102. The axial force acting on the other thrust bearing 124 is received by the support shaft 102 via the wave washer 134, the washer 136 and the C-shaped retaining ring 138. As a result, both the oil seal 126 and the wave washer 134 are compressed in the axial direction. The oil seal 126 and the wave washer 134 are the same as those in the above example.

In the needle bearing 106, when the roller 104 rotates, the sign of the skew angle of the needle 112 becomes constant, and as a result, a leftward axial force acts on the retainer 114 and the outer race 116 at all times. . The leftward axial force is received by the oil seal 126 via the thrust bearing 122.
That is, in this example, the direction of the axial force acting on the retainer 114 and the outer race 116 due to the skew of the needle 112 is constant, and the spring constant and the vibration damping coefficient are larger than the wave washer 134. It is received by the oil seal 126. Therefore, when the roller 104 rotates, vibrations in the axial direction of the roller 104, the outer race 116, the retainer 114, and the needle 112 are reduced as compared with the conventional case where the sign of the skew angle is not constant, and noise is reduced. .
In this example, the thrust bearing 122, the oil seal 126, the washer 128, and the C-shaped retaining ring 132 constitute a main movement limit defining portion, and the thrust bearing 124, the wave washer 134, the washer 136, and the C-shaped retaining ring 138 perform secondary movement. A limit stipulation section is configured.

  In the above example, the support shaft 102 which is the inner peripheral member is fixed to the apparatus main body and does not rotate, and the roller 104 which is the outer peripheral member is rotated. However, the outer peripheral member is fixed to the apparatus main body. When the inner peripheral member is rotated, the cage and the inner peripheral member receive a force in a fixed direction in the axial direction with respect to the outer peripheral member, and vibration and noise are reduced.

  The cages 68 and 114 are tapered in the following manner. That is, the cages 68 and 114 are manufactured by injection molding of a thermoplastic resin containing reinforcing fibers, and at the time of molding, as shown in FIG. 7, a cavity 144 of a mold 142 (details will be described later). In addition, molten thermoplastic resin containing reinforcing fibers is injected from a plurality of (for example, three) gates 146 provided at one end in the axial direction of the cavity 144 and molded.

  An example of a mold for producing a cage by injection molding of a molten thermoplastic resin containing reinforcing fibers as described above is shown in FIGS. The mold 160 forms a cavity 144 having the same shape and size (although there are slight differences) as the retainer 162 in order to form the retainer 162 indicated by a two-dot chain line in FIG. As schematically shown in FIG. 9, a movable mold 164, a fixed mold 166 and a split mold 168 are included. The split mold 168 is divided into a plurality of (eg, two, three, four, etc.) split pieces 170, and the split pieces 170 are held by the movable mold 164 so as to be movable in the radial direction of the cage 162. . The split mold 168 opens and closes by moving in the radial direction, and forms a cylindrical space inside when closed. The movable mold 164 holds the shaft 172 so as to be slidable in the axial direction, and the fixed mold 166 holds the gate forming member 174 so as to be relatively rotatable. The shaft 172 is inserted into a cylindrical space formed by the split mold 168 when the mold 160 is closed, and a hollow cylindrical shape is formed between the outer peripheral surface of the shaft 172 and the inner peripheral surface of the split mold 168. A space is formed. In each split piece 170 of the split mold 168, a plurality of blades 176 shown in FIG. 8 are held so as to be slidable in the radial direction of the hollow cylindrical space, and the mold 160 is shown in a closed state. The leading ends of the blades 176 are caused to enter into the hollow cylindrical space by the non-driving device, and the pockets 178 of the cage 162 are formed. A pillar 180 is formed between the pockets 178 adjacent to each other.

  FIG. 10 shows a plan view of the fixed mold 166 and the gate forming member 174. As is apparent from FIG. 10, there are three gate forming members 174 at positions corresponding to the hollow cylindrical space. Gates 184 are formed at equiangular intervals. The gate forming member 174 is fitted into a fitting hole 190 formed in the fixed mold 166 so that the relative rotation position with respect to the fixed mold 166 can be adjusted. There are various structures for this purpose, but in the example shown in the figure, the bolt hole of the bolt 186 for fixing the gate forming member 174 to the fixed mold 166 is a long hole 188, and the long hole 188 is the bolt 186. Can be adjusted within a movable range. An arm 194 having an L-shaped front shape is provided on the upper surface of the gate forming member 174, and a support pin 196 is erected on the upper surface of the fixed mold 166, and the adjustment is supported rotatably on the support pin 196. A screw 198 is inserted through a through hole 200 formed at the tip of the arm 194, and nuts 201 are screwed onto both sides of the insertion portion. The seat surfaces 202 on both sides that come into contact with the nuts 201 of the arms 194 are formed as partial cylindrical surfaces that protrude toward the corresponding nuts 201. These partial cylindrical surfaces have an axis parallel to the rotation center line of the gate forming member 174 as the center line, and allow relative rotation between the arm 194 and the adjusting screw 198.

  Reference numeral 204 denotes a relative rotational position indicating device that indicates a relative rotational position (see FIG. 8) between the gate 184 and the pocket 178 and the pillar 180. The relative rotational position indicating device 204 is a gate instruction that indicates the position of the gate 184. A line 206, a pocket instruction unit 208 representing half of the pocket 178, and a column instruction unit 210 representing half of the column 180 are provided. That is, in the state where the gate instruction line 206 is at the position shown in the figure, the gate 184 is located at the center in the circumferential direction of the pocket 178, and the gate instruction line 206 is located on the farthest side from the pocket instruction part 208 of the column instruction part 210. In the state of being located at the end, it indicates that the gate 184 is located at the center of the column 180 in the circumferential direction. Further, when the gate instruction line 206 is located at the boundary between the pocket instruction unit 208 and the column instruction unit 210, the gate 184 is located at the boundary between the pocket 178 and the column 180. The operator recognizes the relative rotational positions of the gate 184, the pocket 178, and the pillar 180 from the relative positions of the gate instruction line 206, the pocket instruction portion 208, and the pillar instruction portion 210, while fixing the gate forming member 178. The rotational position relative to 166 can be adjusted. At that time, the relative rotational position can be accurately recognized by the presence of the scale 212. All bolts 186 are slightly loosened, and in the state where one of the two nuts 201 is loosened, the other nut 201 is rotated, the arm 194 is pushed by the nut 201 and the gate forming member 178 is rotated, and the relative rotation When the position reaches a desired position, the one nut 201 is tightened to prevent the gate forming member 174 from rotating, and all the bolts 186 are tightened to fix the gate forming member 174 to the fixed mold 166. It is.

  When the cage 162 is molded, in a state where the mold 160 is closed, molten thermoplastic resin containing reinforcing fibers is injected through the gate 184, and the movable mold 164, the fixed mold 166, the split mold 168, the shaft 172, and the like. The cavity 214 (see FIG. 9) formed by the gate forming member 174, the blade 176 (see FIG. 8) and the like is pressurized and filled. While the thermoplastic resin is solidified and the temperature is still high, the mold 160 is opened, and the cage 162 is taken out.

Thus, when the retainer 162 is molded, depending on the relative rotational position of the gate 184 and the blade 176, that is, the gate 184 is relative to the portion of the cavity 214 corresponding to the pocket 178 and the column 180 of the retainer 162. Thus, it has been confirmed by experiments that the taper and roundness of the molded cage 162 change depending on the relative rotational position. In general, when the gate 184 opens at a position corresponding to the pocket 178 and when it opens at a position corresponding to the pillar 180, the taper direction is reversed. It gets worse. The reason for this is not yet fully understood, but it is speculated that one of the reasons is that the orientation of the reinforcing fibers in the molded cage 162 changes depending on the position of the gate 184.
In any case, the cages 68 and 114 manufactured by this method can be used for both an inner diameter guide type roller bearing and an outer diameter guide type roller bearing.

  The taper and roundness are determined not only by the position of the gate 188 but also the injection temperature of the molten thermoplastic resin into the mold 160, the injection speed, the temperature distribution of each part of the mold, and the molded cage 162. Since it also changes depending on molding conditions such as the temperature at the time of removal, by adjusting the position of the gate 176 and controlling other molding conditions, the target taper (taper can be set to 0) and roundness are adjusted. The holder 162 is obtained. For example, in injection molding, the mold 142 is generally heated, and the thermoplastic resin is heated to a temperature higher than that of the mold. Therefore, the thermoplastic resin flowing into the cavity 144 is cooled and solidified by the mold 142. At this time, by controlling the temperature of the mold 142 and the thermoplastic resin, the cage 68 after molding. , 114 is taken out of the mold 142, the temperature thereof is highest on the gate 146 side and linearly decreases as the distance from the gate 146 increases. The retainers 68 and 114 before being taken out from the mold 142 have a cylindrical shape corresponding to the cavity 144. However, since the shrinkage amount due to the temperature drop after the take-out is closer to the gate 146, the retainer 68, 114 is larger after cooling. The cages 68 and 114 tend to have a tapered cylindrical shape in which both the inner diameter and the outer diameter gradually increase from one end (the end closer to the gate 146) toward the other end, and this fact is utilized.

  As described above, according to the mold 160, the taper and the roundness of the cage 162 can be arbitrarily changed, so that the cage 162 corresponding to the purpose of use can be easily manufactured. For example, although the allowable value of axial vibration that is axial vibration of a device including a needle bearing including the cage 162 is small, the load applied to the thrust bearing is large, the inner peripheral member or the outer peripheral member of the needle When it is allowed that the slip in the axial direction is large, the taper of the cage 162 can be increased to suppress the axial vibration. On the other hand, when it is desired to suppress fine vibration, which is vibration with a small amplitude of a device equipped with a needle bearing, the fine vibration can be suppressed well by reducing the taper and improving the roundness. it can.

FIG. 11 shows an example of selection criteria for taper and roundness when the retainer 162 is manufactured using the mold 160. In the figure, the three columns on the left side indicate requirements for the needle bearing including the cage 162. The axial load is “substantially constant” indicates that the axial load does not vary, and the axial load is “variable”. Indicates that fluctuations in shaft load are allowed. Further, “insufficient” indicates a requirement that it can be used in a state where good lubrication cannot be expected, and “sufficient” indicates that sufficient lubrication is guaranteed. “No” for heat generation / slip indicates a requirement that heat generation or slip is small, and “permission” for heat generation / slip indicates that heat generation or slip is allowed.
The two central columns show selection criteria for taper and roundness, the taper angle indicates the inclination angle on one side of the taper surface, and the roundness indicates the difference between the maximum value and the minimum value of the diameter.
The two columns on the right side show the magnitude of the thrust load and the magnitude of the fluctuation of the thrust load as reference information.

  As is clear from the above description, in the present mold 160, the fixed mold 166 constitutes a mold member that holds the gate forming member 174 rotatably about the central axis of the gate forming member 174, The adjustment screw 198 is supported by a fixed die 166 whose one end is a die member so as to be rotatable about a rotation axis parallel to the central axis of the gate forming member 174, thereby forming a male screw member. The adjusting screw 198 constitutes a screw type adjusting device 203 that adjusts the relative rotational position of the gate forming member 174 and the fixed die 166 in cooperation with the arm 194, the support pin 196, the nut 201, and the like.

  The overall structure of the cage molding die is not limited to that of the above embodiment. Any configuration is possible as long as the relative rotational position between the gate forming member and the other part of the mold can be adjusted, and the relative rotational position between the gate forming member and the other part of the mold can be adjusted. The specific configuration is not limited to the above embodiment. For example, the arm 194 and the adjusting screw 198 can be connected via a joint that allows relative rotation around an axis parallel to at least the rotation center line of the gate forming member, such as a pin joint or a ball joint. is there. Also, after adjusting the relative rotational position, the fixing device for fixing the gate forming member to the other part can also be moved relative to the other part, for example, instead of the combination of the bolt 186 and the long hole 188 in the above embodiment. It is also possible to adopt a configuration in which the pressing member held by the driving member is driven by a driving device to cause the pressing member to press the gate forming member against the other part, thereby fixing the gate forming member to the other part.

It is a perspective view which shows the brake actuator containing the needle bearing which is an example of the holder | retainer manufactured with the metal mold | die which concerns on this invention. It is sectional drawing of the brake actuator of FIG. 1, Comprising: It is sectional drawing which shows the said hydraulic pump. It is a schematic diagram for demonstrating the needle bearing in the said hydraulic pump. It is a graph for demonstrating the said needle bearing. It is another graph for demonstrating the said needle bearing. It is front sectional drawing which shows another example of a needle bearing. It is a figure for demonstrating schematically the method to manufacture the holder | retainer of the needle bearing of the said 2 examples. It is a perspective view which shows notionally an example of the cage molding die suitable for implementation of the said method. It is front sectional drawing which shows the schematic structure of the said retainer shaping die. It is a top view which shows a part of said cage molding die. It is a table | surface which shows an example of the selection criteria of the taper and roundness of a retainer in the case of shape | molding with the said retainer shaping die.

Explanation of symbols

  30: Hydraulic pump 32: Housing 34: Plunger pump part 36: Eccentric cam 42: Plunger 60: Eccentric cam shaft 61, 62 journal part 63: Ball bearing 64: Eccentric shaft part 66: Needle bearing 68: Cage 70: Needle 72: Rings 74, 76: Balancer 78: Wave washer 80: Spacer 82: Oil seal 92: Pocket 102: Support shaft 104: Roller 106: Needle bearing 112: Needle 114: Cage 116: Outer race 122, 124: Thrust bearing 126 : Oil seal 128: Washer 132: C-shaped retaining ring 134: Wave washer 136: C-shaped retaining ring 142: Mold 144: Cavity 146: Game 160: mold 164: movable mold 166: fixed mold 168: split mold 170: split piece 172: shaft 174: gate forming member 176: blade 178: pocket 180: pillar 184: gate 194: arm 196: support pin 198: adjustment Screw 201: Nut 203: Screw type adjusting device 204: Relative rotational position indicating device

Claims (5)

A plurality of rollers arranged between the outer peripheral surface of the inner peripheral side member and the inner peripheral surface of the outer peripheral side member are held in a pocket so as to be able to rotate, and the holder itself rotates around the inner peripheral side member. , A mold for manufacturing by resin injection molding,
A gate for injecting a molten resin into a cavity for molding the cage of the mold is formed in a state of opening one end surface in the axial direction of the cage to a cavity surface for molding, and the gate is formed. The part can be rotated relative to the other part of the mold around the center line of the cavity, and can be fixed to the other part after adjustment of the relative rotational position. Cage mold.   Relative rotation between the part where the gate of the mold is formed and the other part is opened at a position corresponding to the center in the circumferential direction of at least the part where the gate forms the pocket of the cage in the cavity. 2. The cage molding die according to claim 1, which is possible between a relative rotational position where the gate is opened and a relative rotational position where the gate is opened in the center in the circumferential direction of the pillar existing between the adjacent pockets. The mold is
A gate forming member having a circular cross-sectional shape which is a portion where the gate is formed;
A mold member that holds the gate forming member rotatably about the central axis of the gate forming member;
The gate forming member and the die member are provided between the gate forming member and the die member and screwed to each other, and the gate forming member and the die are moved relative to each other in the axial direction due to relative rotation of both screw members. The cage molding die according to claim 1 or 2, comprising a screw type adjusting device for adjusting a relative rotational position with respect to the member. The screw adjusting device;
An arm having one end fixed to the gate forming member and the other end extended to a position facing the mold member;
A male screw member in which one end is rotatably supported by the mold member around a rotation axis parallel to the central axis of the gate forming member, and a male screw is formed on the other end;
The cage molding die according to claim 3, further comprising at least one nut engaged with the arm while being screwed onto the male screw portion.   Relative rotation between the gate forming member and the mold member, which changes with relative rotation between the gate forming member and the mold member, and a portion of the cavity forming the pocket of the cage The cage molding die according to any one of claims 1 to 4, comprising a relative rotational position indicating device that indicates a position.

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