JPH05272611A - Feeder - Google Patents

Abstract

PURPOSE:To provide a brake capable of easily prevent the movement of one of a feed screw and a nut, moving on a rotation axis, threadedly engaged with each other in a feeder, at a movement limit position. CONSTITUTION:The rotation of a ball screw 116 by a D.C. servo motor 128 via a pinion 132 and a gear 126 causes a nut 112 and a hydraulic control piston 96 to move, resulting in the increase or decrease of the fluid pressure in a liquid chamber 98, in its turn, the brake cylinder pressure of a brake. When the nut 112 is retreated, and moreover retreated from a condition, in which the nut 112 abuts on a brake spring 144, three engaging pieces 148, formed on the end part on the nut 112 side of the brake spring 144, are bent in a direction in which the inner diameters of these engaging pieces 148 are contracted, and the movement force of the nut 112 is converted into force in a radial direction. Also the force is doubled to fasten a shaft part 120 and stop the rotation of the ball screw 116 and the movement of the nut 112.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a feeding device for feeding a member to be fed by relative rotation and relative movement of a feed screw and a nut, and more particularly to braking thereof.

[0002]

2. Description of the Related Art Feeders of this kind are widely used. When one of the feed screw and the nut screwed together is rotated by the drive motor, the other moves on the rotation axis of the other and moves the member to be fed. JP-A-64-55468 The feeding device described in the publication is an example. This feeding device is used for feeding a carriage equipped with a magnetic head in a reproducing device for reproducing information stored on a rotating magnetic sheet. The nut is integrally provided on the carriage and screwed into the feed screw, and the feed screw is rotated by the drive motor to move the carriage and the magnetic head reads the information stored in the magnetic sheet.

In this feeding device, the carriage is prevented from moving beyond the movement limit by stopping the rotation of the feed screw. A flange-shaped anti-rotation member is attached to the feed screw, the end surface of the carriage is pressed against the end surface of the anti-rotation member, and the rotation of the feed screw is stopped by the frictional force generated between them, thus stopping the movement of the carriage. is there. Since the threaded portion between the feed screw and the nut generally performs a boosting action, it is easier to stop the rotation of the rotating member than to stop the movement of the moving member. It is possible to prevent the nut from coming off the feed screw and the damage to the nut and the feed screw caused by the nut.

[0004]

However, braking the feeder in this way may still be insufficient. An example thereof is the feeding device of the hydraulic control device described in Japanese Patent Application Laid-Open No. 3-276854.

This hydraulic control device increases or decreases the hydraulic pressure during anti-skid control in the hydraulic brake device, and is designed to be non-rotatable and axially movable concentrically with the pressurizing piston of the master cylinder in the housing. The feed screw is arranged and screwed with a nut that is axially immovable and rotatably provided in the housing. When the nut is rotated by the drive motor, the feed screw moves forward and backward, The pressure piston is moved forward and backward to increase or decrease the hydraulic pressure in the pressure chamber. In this case, the rotation of the nut is stopped to stop the movement of the feed screw.However, in the feed device used to increase or decrease the master cylinder pressure, the reaction force applied from the pressure piston to the feed screw is large. , The rotation torque of the nut that gives the moving force enough to overcome the reaction force to the feed screw is very large.To stop the rotation of the nut, bring the feed screw and nut into contact with each other in the moving direction to generate frictional force. It is not enough to just let them do it.

The present invention has been made in view of the above circumstances and has an object to provide a feeding device having a function of reliably stopping rotation.

[0007]

In order to solve the above-mentioned problems, the present invention provides a feeder having the feed screw, the nut and the drive motor, wherein a member of the feed screw and the nut which is rotated by the drive motor. The gist of the present invention is to provide a braking device that is actuated by an actuating force obtained by multiplying the moving force of a member moving on the rotation axis and stops the rotation of the member rotated by the drive motor.

[0008]

In the conventional braking device that stops rotation by bringing the rotation stop member and the nut provided on the feed screw into contact with each other at the end faces, only an operating force equal to the moving force of the member moving on the rotation axis is obtained. It may not be enough to stop the rotation, but if the rotation is stopped by the operating force that doubles the moving force, the operating force will not be insufficient,
The rotation can be reliably stopped.

[0009]

As described above, according to the present invention, the rotation of the member rotated by the drive motor can be easily stopped, the moving end of the moving member can be reliably defined, and the feeding by excessive movement can be performed. It is possible to reliably avoid damage to screws and nuts.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the drawings by taking as an example the case where the present invention is applied to a hydraulic control device for anti-skid control of a hydraulic brake device for a four-wheel vehicle. In FIG. 3, reference numeral 10 is a master cylinder, and a brake pedal 14 is connected to the master cylinder 10 via a vacuum booster (hereinafter, simply referred to as a booster) 12. The master cylinder 10 has two pressurizing pistons 18,2.
It is a tandem type equipped with 0 in series, and a brake pedal 1
In response to the depression of 4, the hydraulic pressures of approximately the same height are generated in the two independent pressure chambers 22 and 24. Reference numeral 26 is a reservoir that stores the brake fluid at atmospheric pressure. The booster 12 boosts the pedal effort applied to the brake pedal 14, and transmits the boosted pedal effort to the pressurizing piston 20 via the push rod 28.

The hydraulic pressure generated in one pressurizing chamber 22 of the master cylinder 10 is transmitted to the brake cylinders 40 and 42 of each brake of the right front wheel 36 and the left rear wheel 38 by the main fluid passages 30, 32 and 34, and the other. The hydraulic pressure generated in the pressurizing chamber 24 of the left front wheel 52,
Brake cylinders 56, 58 for each brake of the right rear wheel 54
Be transmitted to. Between the main liquid passages 32 and 34, 48 and 50
And proportioning valves 60 and 6 between
Two are provided. This brake system is of X piping type.

A forward movement blocking device 70 is provided between the booster 12 and the master cylinder 10. The advance prevention device 70 includes a bottomed cylindrical housing 72, to which a control piston 74 is fitted in a liquid-tight and slidable manner. The push rod 28 of the booster 12 is engaged with the rear end (the right end in the figure) of the control piston 74, and the pressurizing piston 20 of the master cylinder 10 is engaged with the front end (the left end in the figure). ing. By fitting the control piston 74 into the housing 72, a control liquid chamber 78 is formed in front of the control piston 74 (left side in the drawing).

The volume of the control liquid chamber 78 decreases as the control piston 74 moves forward (moves to the left in the figure), and increases as it moves backward.
The control liquid chamber 78 is connected to the reservoir 26 via a normally open electromagnetic opening / closing valve 80. A check valve 82 that bypasses the solenoid valve 80 is connected to the solenoid valve 80. The check valve 82 allows the flow of the brake fluid from the reservoir 26 side toward the control fluid chamber 78 side and blocks the reverse.

2 of housing 72 and control piston 74
Cup seals 84 and 86 are attached to the one fitting portion, respectively. Each of the cup seals 84 and 86 has a first lip extending from the body toward the control fluid chamber 78 side and a second lip extending toward the outside, and the brake fluid from the control fluid chamber 78 side toward the outside. Both the flow of and the opposite flow are blocked.

Therefore, in the state where the electromagnetic opening / closing valve 80 is closed, the brake fluid is contained in the control fluid chamber 78, the forward movement of the control piston 74 is blocked, and the brake pedal 1
The increase in the hydraulic pressure in the master cylinder 10 due to the depression of 4 is prevented. When the depression of the brake pedal 14 is released with the electromagnetic opening / closing valve 80 closed, the brake fluid flows from the reservoir 26 into the control fluid chamber 78 through the check valve 82, and the control piston 74 retreats. Is acceptable.

A liquid pressure control device 90 is connected to the pressurizing chamber 24 by a liquid passage 88. As shown in FIG. 1, a bottomed cylinder bore 94 is formed in a housing 92 of a hydraulic pressure control device 90, and a hydraulic pressure control piston 96 as a member to be fed is fitted in a liquid-tight manner and slidably in an axial direction. Has been done. A fluid chamber 98 is formed between the fluid pressure control piston 96 and the bottom surface of the cylinder bore 94, and is connected to the fluid passage 88 by a port 100. Further, a spring 102 is arranged in the liquid chamber 98, and the liquid pressure control piston 9
6 is urged in the backward direction in which the volume of the liquid chamber 98 increases.

A spline hole 106 is concentrically formed in the housing 92 following the cylinder bore 94, and the nut 1
12 is fitted in a spline 114 formed on the outer peripheral surface thereof so as to be axially movable and non-rotatable. A ball screw 116 is screwed into the nut 112.

Hydraulic control piston 96 for ball screw 116
The end opposite the side is a non-threaded shank 120.
And is supported by the housing 92 via bearings 122 and 124 so as to be rotatable and immovable in the axial direction.
A gear 126 is non-rotatably attached to a portion of the shaft portion 120 between the bearings 122 and 124.
Output shaft 1 of DC servo motor 128 as a drive motor
It is meshed with a pinion 132 which is attached to the non-rotatable member 30. The shaft portion 134 of the pinion 132 is rotatably supported by the housing 92 by a bearing 136.

Therefore, the ball screw 116 has the gear 12
6, it is rotated by the DC servo motor 128 via the pinion 132, whereby the nut 112 is moved forward and backward. The hydraulic pressure control piston 96 is urged by the spring 102 to follow the movement of the nut 112,
The nut 112 is advanced by the advance of the nut 112, the volume of the liquid chamber 98 is reduced, and the liquid pressure is generated and increased. When the nut 112 is retracted, the hydraulic pressure control piston 96 is also retracted to increase the volume of the liquid chamber 98 and reduce the hydraulic pressure. The hydraulic pressure control piston 96 is formed with a bottomed hole 138 opening to the nut 112 side, and the ball screw 116 is accommodated in the bottomed hole 138 when retracting. Further, the forward movement of the nut 112 is stopped by a stopper 140 provided at the open end of the cylinder bore 94. Originally, the nut 112 cannot be moved until it comes into contact with the stopper 140, but when the nut 112 moves forward excessively due to a control error of the DC servomotor 128, it is stopped by the stopper 140.

The DC servo motor 128 and the pinion 132 are connected to each other via a one-way clutch (not shown). The one-way clutch transmits the rotation on the DC servo motor 128 side to the pinion 132 side, but transmits the rotation on the pinion 132 side to the DC servo motor 128.
It is not transmitted to the side.

A braking spring 144 is attached to the shaft portion 120 of the ball screw 116 and functions as a braking device. As shown in FIGS. 1 and 2, the braking spring 144 has a disc spring shape whose diameter gradually decreases toward the nut 112 side. The large-diameter end of the braking spring 144 is fitted to the end of the fitting hole 145 having a larger diameter than the spline hole 106 adjacent to the bearing 122, and the small-diameter end is adjacent to the threaded portion of the shaft 120. It is fitted in a part with a slight gap left in the radial direction. Also,
As shown in FIG. 2, three notches 146 that open at the tip of the braking spring 144 are formed at equal angular intervals on the small-diameter side of the braking spring 144, thereby forming a fan-shaped three with the rotation axis of the ball screw 116 as the center. The individual engagement pieces 148 are formed.

The electromagnetic opening / closing valve 80 and the DC servo motor 128 are controlled by an anti-skid control unit (hereinafter simply referred to as a unit) 150. Unit 1
Reference numeral 50 is mainly a computer having a CPU, a ROM, a RAM and a bus connecting them.
The unit 150 is supplied with the detection results of the rotation speed sensors 152, 154 for detecting the rotation speeds of the left and right front wheels 52, 36 and the rotation speed sensors 156, 157 for detecting the rotation speeds of the left and right rear wheels 38, 54, respectively. 15
0 is based on that, wheel speed, wheel acceleration, vehicle speed,
Calculate the slip ratio etc.

The unit 150 is also connected to the electromagnetic opening / closing valve 80 and also to the DC servo motor 128 via the motor control circuit 158. Based on the result of the above calculation, the electromagnetic on-off valve 80 and the DC servo motor 128 are controlled to control the slip ratios of the wheels 36, 38, 52, 54, etc. to values as close to appropriate values as possible.

In the hydraulic brake device constructed as described above, the electromagnetic opening / closing valve 80 is normally opened and the control liquid chamber 78 is communicated with the reservoir 26. Therefore, when the brake pedal 14 is depressed, the control piston 7
4 is advanced, the pressurizing pistons 18, 20 are advanced, hydraulic pressure is generated in the pressurizing chambers 22, 24, and rotation of the wheels is suppressed. At this time, the hydraulic pressure having the same height as the hydraulic pressures of the pressurizing chambers 22 and 24 is transmitted to the liquid chamber 98, but since the backward movement of the hydraulic pressure control piston 96 is prevented by the one-way clutch, the hydraulic chamber 98 has It does not increase in volume.

When the stepping force of the brake pedal 14 becomes excessive and the slip ratio of the wheels exceeds the proper range, the unit 150 switches the electromagnetic opening / closing valve 80 to the closed state to prevent the control piston 74 from advancing. The hydraulic pressure control piston 96 is operated. First, the DC servomotor 128 is rotated through the motor control circuit 158 in a direction to increase the volume of the liquid chamber 98, whereby the hydraulic pressure of the liquid chamber 98, and thus the hydraulic pressure of the pressurizing chambers 22 and 24 and the brake cylinder. The hydraulic pressure is reduced. As a result, the reaction force applied from the pressure piston 20 to the control piston 74 decreases.

Therefore, as long as the stepping force of the brake pedal 14 is kept constant, the force balance of the control piston 74 is broken and the control piston 74 tries to move forward.
Since the outflow of the brake fluid from the control fluid chamber 78 is blocked by the electromagnetic on-off valve 80 in the closed state, the control piston 74 cannot move forward, and the amount corresponding to the amount of decrease in the reaction force from the pressurizing piston 20 is large. Only then does the hydraulic pressure in the control liquid chamber 78 increase. That is, since the electromagnetic opening / closing valve 80 is closed, the control piston 74 is prevented from moving forward, so that the control piston 74 moves forward even if the hydraulic pressure in the pressurizing chambers 22 and 24 decreases. It does not increase the hydraulic pressure in the pressure chambers 22 and 24.

If the slip ratio begins to recover due to the above pressure reduction, is the retreat of the hydraulic pressure control piston 96 stopped?
Alternatively, it is advanced so that the volume of the liquid chamber 98 is maintained or reduced, and the hydraulic pressure thereof, and thus the brake cylinder hydraulic pressure is maintained or increased. By this pressure increase, the reaction force from the pressure piston 20 to the control piston 74 increases,
The hydraulic pressure in the liquid chamber 78 is reduced by an amount commensurate with the increase, the balance of the force on the control piston 74 is maintained, and the control piston 74 continues to stand still.

As described above, the unit 150 controls the DC servomotor 128 to increase or decrease the volume of the liquid chamber 98 regardless of the depression of the brake pedal 14 to reduce, hold or increase the brake cylinder hydraulic pressure, and However, if the brake pedal 14 is released during the anti-skid control, the control piston 74 moves backward, and the pressurizing pistons 18 and 20 also move backward accordingly. , 24 is reduced to the height desired by the driver.

When the anti-skid control is performed as described above, the forward and backward movements of the nut 112 in the hydraulic control device 90 are stopped by stopping the DC servo motor 128.

However, the anti-skid control unit 15
0, the nut 11 due to a failure of the motor control circuit 158, etc.
When 2 is retracted abnormally, it is stopped by the braking spring 144. The nut 112 retracts and the braking spring 14
4 and then retract further from that state, the engaging piece 14
8 is bent in the direction in which the small diameter portion of the braking spring 144 contracts, and the shaft portion 120 of the ball screw 116 is tightened. The braking spring 144 has a tapered shape, and includes the engaging piece 148 and the shaft portion 12.
Since the angle formed with 0 is 60 ° or more, the braking spring 144 performs a boosting action similar to the toggle mechanism, and the small diameter portion is reduced in diameter while the large diameter portion is enlarged.

As a result, a large frictional force is generated between the small diameter portion of the braking spring 144 and the ball screw 116, and a large friction is also generated between the large diameter portion of the braking spring 144 and the inner peripheral surface of the fitting hole 145. A force is generated and the rotation of the ball screw 116 is reliably stopped. In the hydraulic brake system, the brake cylinder pressure required to suppress wheel rotation is high,
In order to generate such a liquid pressure in the liquid chamber 98, it is necessary that the moving force of the nut 112 is large.
In order to generate a large moving force in 2, the ball screw 116
The rotation torque of the ball screw also increases, but such a ball screw 1
The rotation of 16 can be surely stopped by the boosted force.

After the rotation of the ball screw 116 and the movement of the nut 112 are stopped in this way, if the DC servomotor 128 is rotated in the opposite direction, the nut 1
12 is separated from the braking spring 144. When the reverse rotation of the DC servo motor 128 is started, the braking spring 144 prevents the rotation of the ball screw 116, but if the DC servo motor 128 is rotated by the same force as in the normal rotation, the ball screw 116 is rotated in the reverse direction. Can be made
When the nut 112 is in contact with the braking spring 144, the braking spring 144 applies a forward force to the nut 112. While this force acts as a load when the DC servo motor 128 rotates in the forward direction, it acts as an assisting force when the DC servo motor 128 rotates in the reverse direction, so that the load of the DC servo motor 128 decreases accordingly and the DC servo motor 128 is in the operating state. The ball screw 11 resists the braking force of the braking spring 144.
6 can be rotated in the reverse direction.

The abnormal advance of the nut 112 is directly stopped by the stopper 140, but in this case, the liquid chamber 9
Since the high hydraulic pressure of 8 acts in the direction to prevent the nut 112 from advancing, the contact force of the nut 112 with the stopper 140 is not so large and no problem occurs.

As is apparent from the above description, in the present embodiment, the axial moving force of the nut 112 is converted into a radial force by the braking spring 144 itself, and is also boosted and boosted. Ball screw 116 due to braking force
Rotation is stopped, and as a result, the movement of the nut 112 is also stopped.

However, if the viewpoint is changed, the braking spring 144
Is also a braking device that stops the movement of the nut 112 while providing a cushioning action. DC servo motor 128, pinion 132, gear 126, ball screw 116, nut 11
2. The hydraulic control piston 96 and the like have inertia, and in order to stop them, the kinetic energy they have must be removed. Therefore, when the nut 112 is brought into contact with a rigid stopper to stop the movement, the kinetic energy is instantaneously removed, and the nut 112 and the stopper, and thus the nut 112 and the ball screw 116. It is unavoidable that a large force acts between and. On the other hand, in this embodiment, the nut 112 first comes into contact with the braking spring 144 to elastically deform it, and then the braking spring 144 acts on the ball screw 116 to prevent its rotation, and the braking Spring 1
Since the braking force of 44 gradually increases as the nut 112 moves, this braking device buffers the movement of the nut 112.

Another embodiment of the present invention is shown in FIGS. In the present embodiment, the band 160 is wound around the shaft portion 120 of the ball screw 116, and the rotation of the ball screw 116 is stopped by the frictional force generated between the band 160 and the shaft portion 120. The other structure is the same as that of the above-described embodiment, and the corresponding portions are denoted by the same reference numerals and the description thereof is omitted.

A pair of support plates 162 are erected on the outer surface of the housing 92 of the hydraulic control device 90, and a lever 164 is orthogonal to the rotation axis of the ball screw 116 by a shaft 166 between the support plates 162. It is attached so as to be rotatable around its axis. The lever 164 has an L-shape, and one arm portion 168 of the L-shape has the other arm portion 17.
The length of the arm portion 168 is approximately three times as long as that of the arm portion 168.
As shown in FIG. 5, it projects inward and is aligned with the ball screw 116 and faces the nut 112. Also,
A long hole 174 is formed at the protruding end of the other arm 170, and is rotatably fitted to a shaft 176 protruding from one end of the band 160. The other end of the band 160 is fixed to the housing 92.

A return spring 177 is bridged between the arm portion 168 of the lever 164 and the housing 92 to urge the lever 164 counterclockwise in FIG. As a result, when the rotation of the ball screw 116 is not stopped, the stopper 178 formed on the side surface of the arm portion 168 contacts the end surface of the opening 172, and the band 16
0 does not contact the shaft portion 120 and is kept in a state where the rotation of the ball screw 116 is not stopped.

When the nut 112 retracts and further retracts from the state of contacting the arm portion 168 of the lever 164, the lever 164 rotates clockwise in FIG.
The rotation of the ball screw 116 is stopped by tightening 0 and restraining the shaft portion 120. In this case, the moving force of the nut 112 is boosted by the lever ratio between the arm portions 168 and 170 of the lever 164 and is applied to the band 160, so that the rotation of the ball screw 116 is reliably stopped. In this embodiment, the band 160 and the lever 1
The reference numeral 64 constitutes a braking device.

The braking device of this embodiment also has a nut 11 for cushioning.
It functions as a braking device that stops the movement of 2. The band 160 and the lever 164 forming the braking device are elastically deformable to some extent, and the elastic deformation is enlarged and appears at the tip of the arm portion 168 of the lever 164, so that the arm portion 168 abuts the nut 112. After the nut 112
Therefore, the nut 112 can be moved while applying a force opposite to the moving direction, and the nut 112 is stopped as a buffer.

Yet another embodiment of the present invention is shown in FIGS.
Shown in. In the present embodiment, the rotation of the ball screw 116 is stopped by stopping the rotation of the pinion 132. Bearing 13 of shaft portion 134 of pinion 132
A band 180 is wound around the end protruding from 6. As shown in FIG. 8, the band 180 has one end fixed to the housing 92 and the other end rotatably attached to one end of the lever 182. Lever 182 is shaft 1
The first hydraulic cylinder 188 and the second hydraulic cylinder 1 are attached to the housing 92 by 84 so as to be rotatable around an axis orthogonal to the rotation axis of the ball screw 116.
It is rotated by 90.

The first hydraulic cylinder 188 has a housing 9
The piston 194, which is attached to the outer surface of the portion forming the second spline hole 106 and is movably fitted in the cylinder housing 192, is moved by the rotation of the lever 196. The lever 196 is attached to the housing 92 by a shaft 198 so as to be rotatable about an axis orthogonal to the rotation axis of the ball screw 116, and one end of the lever 196 is projected from the opening 200 formed in the housing 92 to the outside of the housing 92. The rod 202 is rotatably connected to the piston 194. Further, the other end of the lever 196 is projected into the spline hole 106, aligned with the ball screw 116 and opposed to the nut 112 as shown in FIG. 7.

The hydraulic chamber 204 formed in the cylinder housing 192 is communicated with the hydraulic chamber 208 of the second hydraulic cylinder 190 by the liquid passage 206. Piston 2 movably fitted in the second hydraulic cylinder 190
12 is rotatably connected to the other end of the lever 182 by a rod 214. The diameter of the piston 212 is larger than the diameter of the piston 194 of the first hydraulic cylinder 188.

The piston 212 of the second hydraulic cylinder 190 has a hydraulic chamber 208 inside the cylinder housing 210.
Return spring 21 arranged on the opposite side of
5 is urged to the hydraulic chamber 208 side, and the ball screw 11
When the rotation of 6 is not stopped, it is brought into contact with a stopper 216 provided in the hydraulic chamber 208. As a result, the lever 182 is held in the position rotated clockwise in FIG. 6, the band 180 is loosened and separated from the shaft portion 134,
The pinion 132 is kept in a state in which it is allowed to rotate.

When the nut 112 retracts and further abuts against the lever 196, the lever 196 is rotated clockwise in FIG. 6, and the first hydraulic cylinder 188 is rotated.
The piston 194 is moved forward to generate hydraulic pressure in the hydraulic chamber 204. This hydraulic pressure is supplied to the hydraulic chamber 208 of the second hydraulic cylinder 190, and the piston 212 is retracted. Thereby, the lever 182 is rotated, and the band 1
80 is tightened to restrain the shaft portion 134, and the pinion 1
By stopping the rotation of 32, the rotation of the ball screw 116 is stopped. The piston 212 of the second hydraulic cylinder 190 has a diameter larger than that of the piston 194 of the first hydraulic cylinder 188, and the moving force of the nut 112 is boosted by the area ratio of the pistons 194, 212 and the band 1 is moved.
In addition to 80, rotation of the pinion 132 is stopped.

In this embodiment, the band 180, the levers 182, 196, the first and second hydraulic cylinders 188, 1
90 constitutes a braking device. Further, in this embodiment, the rotation of the pinion 132 is stopped in order to stop the rotation of the ball screw 116. However, the rotation torque of the pinion 132 is smaller than that of the ball screw 116, and the rotation of the ball screw 116 is stopped directly. It can be stopped more easily.

Yet another embodiment of the present invention is shown in FIGS. 9 and 1.
It shows in 0. In this embodiment, similarly to the embodiment shown in FIGS. 1 to 3, the rotation of the ball screw 116 is stopped by using the braking spring 220 having the three engaging pieces 218.
Further, a spline 222 is provided at the end of the braking spring 220 on the side opposite to the nut 112 so as to engage with the spline hole 106 and prevent rotation. Also, bearing 1
A washer 224 is provided on the end surface of the braking spring 220 on the side of the braking spring 220 so that the end of the braking spring 220 does not bite into the outer race of the bearing 122.

In this embodiment, as in the embodiment shown in FIGS. 1 to 3, the engagement piece 218 is reduced in diameter to restrain the shaft portion 120 and the rotation of the ball screw 116 is stopped, but the braking spring 220 is Since the rotation is blocked, the rotation of the ball screw 116 can be surely stopped when the shaft portion 120 is engaged, without the risk of being caught around the ball screw 116.

FIG. 11 shows still another embodiment of the present invention.
In this embodiment, the nut 230 and the shaft portion 2 of the ball screw 232.
The rotation of the ball screw 232 is stopped by taperingly fitting with 34. Therefore, a tapered hole 236 whose diameter increases toward the opening is formed at the end of the nut 230 on the side facing the shaft portion 234, and the shaft portion 234 is formed with a tapered portion 238 corresponding to the tapered hole 236. ..

When the nut 230 moves backward, the tapered hole 23
6 tightly fits into the taper portion 238 to fit the ball screw 232.
Is stopped from rotating. In this case, due to the wedge effect due to the fitting of the tapered hole 236 and the tapered portion 238, the moving force of the nut 230 is boosted and applied to the shaft portion 234, and the rotation of the ball screw 232 is reliably stopped. In this embodiment, the tapered hole 236 and the tapered portion 238 are used.
Constitutes the braking device.

FIG. 12 shows still another embodiment of the present invention.
In this embodiment, the nut 240 rotates and the ball screw 242
The present invention is applied to the feeding device of the hydraulic pressure control device 248 in which the hydraulic pressure control piston 244 is moved by moving on the rotation axis of the nut 240, and the volume of the liquid chamber 246 is increased or decreased. A hydraulic control piston 244 is formed at one end of the ball screw 242, and the housing 252
Liquid-tightly and axially slidably fitted into the cylinder bore 254 of the cylinder bore 254 to form a liquid chamber 246 between the cylinder bore 254 and the bottom surface of the cylinder bore 254.
Are formed. Further, a spline shaft 256 is formed at the other end of the ball screw 242 and is fitted in a spline hole 258 formed in the housing 252, and is supported so as to be movable in the axial direction and not relatively rotatable.

The nut 240 is mounted on the housing 252 by the bearing 2
A gear 264 is integrally formed and is meshed with a pinion 268 rotated by a DC servo motor 266 while being supported by 60 and 262 so as to be rotatable and immovable in the axial direction. Therefore, the nut 24
0 is rotated by the DC servo motor 266 via the gear 264 and the pinion 268, whereby the ball screw 242 is moved forward and backward to increase or decrease the volume of the liquid chamber 246.

An annular projection 272 is formed on the end surface of the nut 240 on the hydraulic pressure control piston 244 side.
A spline hole 274 is formed inside thereof, and one end of the braking spring 276 is fitted therein. The braking spring 276 is
It has a disc spring shape, and a spline is formed at the end on the large diameter side and is fitted into the spline hole 274, and the end on the small diameter side is fitted to the ball screw 242 with a gap left in the radial direction. , Is rotated with the nut 240.
Further, the threaded portion of the ball screw 242 and the hydraulic control piston 2
44, the hydraulic control piston 244 has a diameter
A cylindrical portion 278 that is smaller and larger than the screw portion of the ball screw 242 is formed, and a taper portion 280 that connects the cylindrical portion 278 and the screw portion of the ball screw 240 is formed.

Similarly, an annular projection 282 is formed on the end surface of the nut 240 on the side of the spline shaft 256, and a spline hole 284 is formed inside thereof, so that one end of a disc spring-shaped braking spring 286 is splined. It is fitted. The end of the braking spring 286 on the small diameter side is the ball screw 2
42 has an inner diameter slightly larger than the threaded portion of 42, and the braking spring 28
6 rotates with nut 240. A cylindrical portion 290 and a tapered portion 292 are formed between the shaft portion 288 and the spline shaft 256.

The forward movement of the ball screw 242 (moving to the right in FIG. 12) is normally stopped by stopping the DC servomotor 266, but if it is further advanced from that state for some reason, the shaft portion of the ball screw 242 is stopped. 288
The cylindrical portion 290 formed on the inner surface of the spline shaft 2 is guided by the tapered portion 292 and fitted into the braking spring 286.
The end surface of 56 abuts on the braking spring 286 to bend the small-diameter end portion in a direction to reduce the diameter. As a result, the moving force applied from the ball screw 242 to the braking spring 286 is converted into a radial force and is boosted and applied to the nut 240,
Stop its rotation.

When the ball screw 242 moves backward (moves leftward in FIG. 12), the hydraulic pressure control piston 2
The cylindrical portion 278 formed on the 44 side is fitted into the small diameter portion of the braking spring 276 by the guide of the taper portion 280, and the end surface of the hydraulic pressure control piston 244 abuts against the small diameter portion and bends in a direction to reduce the diameter. As a result, the rotation of the nut 240 is stopped and the movement of the ball screw 242 is stopped.

Although a ball screw is used as the feed screw in each of the above embodiments, a feed screw having no balls may be used. Further, the feed mechanism and the braking device of each embodiment can be adopted by appropriately changing the combination.

Further, in each of the above-described embodiments, when the braking device is in operation, the drive motor is simply rotated in the direction opposite to that in which the braking device is in operation, whereby the braking device is inactive. However, if this is difficult, if the starting current is intermittently supplied to the drive motor multiple times, the braking device in the operating state can be reliably released. In this case, if the starting current is made larger than the steady drive current, the purpose can be achieved more reliably.

Further, the present invention can be widely applied not only to the feed device of the hydraulic control device for anti-skid control but also to the feed device provided with the nut, the feed screw and the drive motor.

In addition, the present invention can be implemented in various modified and improved modes based on the knowledge of those skilled in the art without departing from the scope of the claims.

[Brief description of drawings]

FIG. 1 is a front cross-sectional view showing a hydraulic pressure control device including a feeding device according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a system diagram of a hydraulic brake device in which anti-skid control is performed by the hydraulic pressure control device.

FIG. 4 is a front sectional view showing a main part of a fluid pressure control device including a feeding device according to another embodiment of the present invention.

5 is a sectional view taken along line VV in FIG.

FIG. 6 is a front cross-sectional view showing a main part of a hydraulic control device equipped with a feeding device that is still another embodiment of the present invention.

7 is a sectional view taken along line VII-VII in FIG.

8 is a sectional view taken along line VIII-VIII in FIG.

FIG. 9 is a front sectional view showing a main part of a hydraulic control device including a feeding device according to another embodiment of the present invention.

10 is a cross-sectional view taken along line XX in FIG.

FIG. 11 is a front cross-sectional view showing a main part of a hydraulic control device including a feeding device that is still another embodiment of the present invention.

FIG. 12 is a front sectional view showing a main part of a hydraulic control device including a feeding device according to still another embodiment of the present invention.

[Explanation of symbols]

 90 hydraulic control device 96 hydraulic control piston 112 nut 116 ball screw 128 DC servo motor 144 braking spring 160 band 164 lever 180 band 182 lever 188 first hydraulic cylinder 190 second hydraulic cylinder 196 lever 220 braking spring 230 nut 232 Ball screw 236 Tapered hole 238 Tapered portion 240 Nut 242 Ball screw 244 Fluid pressure control piston 266 DC servo motor 276, 286 Braking spring

Claims (1)

[Claims] 1. A feed device in which one of a feed screw and a nut screwed with each other is rotated by a drive motor so that the other moves along the rotation axis of the one and moves a member to be fed. A feeding device provided with a braking device that is actuated by an actuating force that doubles the moving force of the other and stops rotation of the one.