JPH1162848A - Actuator for brake fluid presure controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent vibration (noise) of a motor by eliminating a clearance between a sliding bearing and a shaft. SOLUTION: The surface for bearing a sliding bearing 19 and the surface of a shaft 17, to be brought in contact with the sliding bearing 19 are formed into taper shapes so as to be extended in the direction of a rotor 15, and the sliding bearing 19 can be moved in the direction of the rotor 15. Concretely, the contact surfaces of a window part 10b of a motor yoke 10 and the sliding bearing 19 is formed into screw shapes, the sliding bearing 19 is screwed, and the sliding bearing 19 can be moved in the direction of the rotor 15. Therefore, a clearance between the shaft 17 and the sliding bearing 19 is eliminated, and vibration (noise) of a motor 1 can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an actuator for a brake fluid pressure control device, and is particularly suitable for application to an antilock brake device (hereinafter referred to as an ABS device) and a traction control device.

[0002]

2. Description of the Related Art Conventionally, an actuator for an ABS apparatus has a structure in which a shaft is supported by two or more ball bearings. At least one of the ball bearings applies a load (pressurized force) to an outer ring in a shaft axial direction. ), The gap in the ball bearing (the gap between the rolling element and the outer or inner ring)
To prevent ball bearing vibration (noise). That is, since the ball bearing can receive a load in the shaft axial direction, the gap in the ball bearing can be filled as described above.

However, since these ball bearings are expensive,
It has been proposed that at least one of two or more ball bearings be a sliding bearing (Japanese Patent Laid-Open No. 8-74732).

[0004]

However, if at least one of the two or more ball bearings is a slide bearing, a gap is generated between the slide bearing and the shaft. There is a problem that the motor vibrates (generates noise) due to the gap between them.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and when a sliding bearing is used as a bearing used for supporting a shaft, a clearance between the sliding bearing and the shaft is eliminated to prevent motor vibration (noise). It is an object of the present invention to provide a brake fluid pressure control actuator that can perform pressure control.

[0006]

In order to achieve the above object, the following technical means are employed. According to the first to third aspects of the present invention, both the bearing surface of the sliding bearing (19) and the surface of the shaft (17) that comes into contact with the sliding bearing (19) are tapered to expand in the direction of the rotor (15). And the sliding bearing (19) has a rotor (1).
It is characterized by being movable in the direction of 5).

As described above, the sliding bearing (19) of the shaft (17) and the bearing surface of the sliding bearing (19).
When the slide bearing (19) is moved in the direction of the rotor (15), the shaft (1) is moved by the slide bearing (19).
7) An axial load can be applied. As a result, a gap between the slide bearing (19) and the shaft (17) can be eliminated, and vibration (noise) of the motor (1) due to the gap can be prevented.

The shaft (17) has a sliding bearing (1).
9) and the ball bearing (18), if the outer ring (18b) of the ball bearing (18) is prevented from moving in the axial direction of the shaft (17), the sliding bearing (19)
Is moved, the gap between the ball bearings (18) can be eliminated, so that even in such a case, the vibration (noise) of the motor (1) can be prevented.

In the invention according to claim 2, the shaft (17) is divided into the first shaft (17a) and the second shaft (17a).
A single shaft (b), wherein a rotor (15) is arranged on a first shaft (17a), and an eccentric part (24) is arranged on a second shaft (17b). I have. Thus, the divided shaft (1)
In the case of using (7), the load received by the second shaft (17b) from the pump (5) via the eccentric part (24) is not transmitted to the first shaft (17a) provided with the rotor (15). The rotor (15) can rotate without being affected by the load. Therefore, the vibration of the motor (1) due to the load from the pump (5) can be more effectively prevented.

According to the third aspect of the present invention, the contact surface between the window (10b) provided in the motor yoke (10) and the slide bearing (19) is formed in a screw shape, and the slide bearing ( The sliding bearing (19) moves in the direction of the rotor (15) by screwing the sliding bearing (19) to the window (10b). As described above, if the slide bearing (19) is formed into a screw shape and the slide bearing (19) can be inserted into the motor yoke (10), the slide bearing (19) is tightened by screwing the slide bearing (19). Can move in the direction of the rotor (15).

According to the fourth aspect of the present invention, the positioning of the slide bearing (19) is adjusted based on the rotational torque of the slide bearing (19) when the slide bearing (19) is screwed to the window (10b). It is characterized by performing. As described above, if the positioning of the slide bearing (19) is adjusted based on the rotational torque of the slide bearing (19),
The clearance between the sliding bearing (19) and the shaft (17) can be eliminated without the sliding bearing (19) excessively applying an axial load to the shaft (17). Thereby, durability and the like of the motor (1) can be secured.

According to a fifth aspect of the present invention, the positioning of the slide bearing (19) is performed based on a current value of a current flowing through the rotor (15) in a no-load state before screwing the slide bearing (19). Even if the adjustment is performed, the same effect as the third aspect can be obtained. According to a sixth aspect of the present invention, after the positioning of the slide bearing (19) is adjusted, the slide bearing (19) is fixed to the window (10b).

If the sliding bearing (19) is fixed to the window (20b) after the positioning and adjustment as described above,
The sliding bearing (19) can be held at the position where it has been positioned, and the state in which the gap between the sliding bearing (19) and the shaft (17) has been eliminated can be maintained. The sliding bearing (19) is fixed to the window (10b) by bonding the sliding bearing (19) to the window (10b) or by caulking a part of the motor yoke (10). Can be.

[0014]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a first embodiment of the present invention. (First Embodiment) FIG. 1 shows a partial sectional view when the motor 1 is assembled to an ABS control actuator.

Here, the ABS control actuator is to prevent the wheels from becoming locked by controlling the brake fluid pressure in the main line connecting the master cylinder and the wheel cylinder (not shown). Device. Specifically, the ABS control actuator includes a reservoir for releasing brake fluid in the main pipeline during pressure reduction control;
A pressure-intensifying control valve that controls the communication / shutoff of the main line, a pressure-reducing control valve that controls the brake fluid in the main line to be released when the pressure-reducing control is performed, and a brake accumulated in the reservoir. A pump 5 for returning liquid to a master cylinder or the like, a motor 1 for driving the pump, and an electronic control for generating an electric signal to the pressure increasing control valve, the pressure reducing control valve, and the motor 1 via electric wiring. Equipment (hereinafter referred to as EC
U) is housed in the housing 8 and integrally formed.

The housing 8 comprises a first housing 8a and a second housing 8b.
a and the second housing 8b are integrated by being screwed and fixed. At this time, the motor 1 is partially inserted into the recess provided in the first housing 8a,
A portion of the first housing 8a is fixed to the first housing 8a by a caulking portion 8c. Thus, by inserting the motor 1 into the recess of the first housing 8a, the size of the entire ABS control actuator is reduced.

Hereinafter, the structure and operation of the motor 1 will be specifically described. The motor 1 comprises a cup-shaped motor yoke 10, at least two permanent magnets 11, a coil 1
A rotor 15 having a commutator 14 electrically connected to the core 13 and the coil 12 around which the coil 2 is wound;
A brush 16 having a commutator 14 and a sliding contact;
A shaft 17 serving as a rotation axis of the rotor 15;
A ball bearing 18 and a sliding bearing 19 that support the shaft 7 are provided.

The magnet 11 is fixed to the inner periphery of the motor yoke 10 by an adhesive so as to face the outer periphery of the core 13, and the interval S between the magnet 11 and the core 13 is constant (for example, 0.1 mm). (About 1 mm).
The motor yoke 10 is located between the entrance of the cup-shaped motor yoke 10 and the portion where the magnets 11 are arranged.
Is provided with an opening 10a serving as a notch (slit), and a part of the first housing 8a is swaged into the opening 10a to fix the motor 1 to the first housing 8a.

The brush 16 comes into contact with the commutator 14 by the elastic force of the spring 16a, and an electric signal from the ECU is output to the coil 12 via the brush 16 and the commutator 14. I have. A magnet 11 is fixed to the inner periphery of the motor yoke 10, and an electric signal from the ECU substrate 7 is output to the coil 12 at a portion of the inner periphery of the motor yoke 10 where the magnet 11 is not arranged. The wiring section 20 is arranged. The wiring portion 20 is integrally formed of resin and a lid portion 21 that fixes the brush 16 and serves as a lid of the motor yoke 10.

One end of the shaft 17 is supported by a slide bearing 19. Specifically, the bearing surface (inner diameter) of the sliding bearing 19 and the sliding bearing 1 of the shaft 17
Both ends of the sliding bearing 19 are tapered so as to expand in the direction of the core 13. The tapered portion of the sliding bearing 19 supports the shaft 17.

The sliding bearing 19 is provided with the motor yoke 1.
0 is fixed in a state of being in contact with a window 10b having a hollow bottom projecting at the center of the bottom surface. Specifically, the outer peripheral wall of the slide bearing 19 is formed in a male screw shape, and the window portion 10b
The inner peripheral wall of the sliding bearing 1 is formed in a female screw shape.
9 is screwed to the window 10b. After the screws are tightened, the slide bearing 19 is adhered and fixed to the window 10b.

When the sliding bearing 19 is fixed to the window 10b, the rotational torque at the time of fixing the sliding bearing 19 with screws is measured by using a torque wrench or the like, and the positioning of the sliding bearing 19 is adjusted. The load on the shaft 17 in the axial direction is set to a predetermined amount. That is, as shown by the characteristics of the rotational torque and the axial load applied to the shaft 17 shown in FIG. 2, the axial load applied to the shaft 17 increases exponentially with an increase in the rotational torque, and If the screwing and fixing of the bearing 19 is arbitrarily performed, the axial load applied to the shaft 17 becomes excessive. Therefore, by setting the value of the torque wrench so that the axial load applied to the shaft 17 becomes a predetermined value (for example, about 10 kgf), the durability of the ball bearing is ensured.

On the other hand, the other end of the shaft 17 is
8 supported. Inner ring 1 of this ball bearing 18
8 a is fixed to the shaft 17, and the outer ring 18 b is locked by a step 21 a formed on the lid 21. As described above, since a load is applied to the shaft 17 in the axial direction, the inner race 18 of the ball bearing 18
a moves in the loaded direction, but the outer ring 18b locked by the lid 21 cannot move in the loaded direction. Pressed. Thereby, the ball bearing 1
8, that is, the inner ring 18 a and the outer ring 18 b can eliminate the gap. Furthermore, the sliding bearing 1
9 is tapered, and a load in the axial direction is applied to the shaft 17 at the tapered portion.
The gap between the shaft and the shaft 17 can be eliminated.

A cam (eccentric portion) 24 composed of a ball bearing is arranged on the shaft 17 in an eccentric state, and the pump 5 is driven by the eccentric rotation of the cam 24. The motor 1 thus configured is
It is driven by an electric signal from the ECU. In other words, EC
An electric current is passed through the coil 12 based on the electric signal from U, and the core is rotated by the current flowing through the coil 12 and the magnetic force of the magnet 11, and the shaft 17 and the cam 24 are rotated.

The rotation of the cam 24 causes the plunger 5a of the pump 5 to perform a piston movement, so that the pump 5 sucks the brake fluid in the reservoir and discharges it to the master cylinder and the like. This cam 2
When rotating 4, the shaft 17 is rotated,
Since the rotating shaft 17 is supported by the ball bearing 18, the inner ring 18 b of the ball bearing 18 rotates together with the shaft 17.

At this time, as described above, the sliding bearing 1
9 has a tapered inner periphery, a load is applied in the axial direction to the shaft 17, a gap in the ball bearing 18, and
Since the gap between the slide bearing 19 and the shaft 17 is eliminated, vibration of the shaft 17 even when the shaft 17 rotates, and thus vibration of the motor 1 during ABS control, can be prevented.

Since the magnitude of the axial load applied to the shaft 17 is measured by the rotational torque of the sliding bearing 18 fixed with screws, the problem of durability of the ball bearing 18 can be solved. it can. The pump 5
Impact load on shaft 17 and shaft 1
It is applied to the ball bearing 18 via 7. Since the pump 5 sucks and discharges the brake fluid, the ball bearing 18
The impact load on the shaft 1 becomes particularly large, and if the gap in the ball bearing 18 and the gap between the sliding bearing 19 and the shaft 17 are not eliminated, the shaft 1
The vibration (noise) of No. 8 becomes very large. Therefore, it is particularly effective to eliminate the gap in the ball bearing 18 and the gap between the sliding bearing 19 and the shaft 17 as shown in the present embodiment.

(Second Embodiment) FIG. 3 shows a case where the motor 1 according to the second embodiment is assembled to the first housing 8a.
Shown in In the first embodiment, one end of the shaft 17 is supported by the ball bearing 18 and the other end is supported by the slide bearing 19; however, in the present embodiment, both ends of the shaft 17 are supported by the slide bearing. Note that the configuration of the motor 1 according to the present embodiment is substantially the same as that of the first embodiment, and therefore only the differences from the first embodiment will be described.

As shown in FIG. 3, a slide bearing 30 is provided between the commutator 14 and the cam 24, and the shaft 17 is supported by the slide bearing 30 and the slide bearing 19. The slide bearing 30 includes the lid 2
1 and the bearing surface (inner diameter) is the core 13
Has a tapered shape extending in the direction of. Also,
The surface of the shaft 17 that comes into contact with the slide bearing 30 is formed in a tapered shape in accordance with the shape of the slide bearing 30.

As described above, when both sides of the shaft 17 are supported by the slide bearings 19 and 30, the bearing surfaces of the slide bearings 19 and 30 are both tapered so as to expand in the direction of the core 13. Therefore, when a load in the axial direction is applied to the shaft 17 by the slide bearing 30, the shaft 1 is moved by the slide bearing 19 and the slide bearing 30.
Since the shaft 7 can be pressed down in the axial direction, the gap between the slide bearing 19 and the slide bearing 30 and the shaft 17 can be eliminated. As a result, the vibration of the shaft 17 and, consequently, the vibration of the motor 1 during the ABS control can be prevented as in the first embodiment.

In this embodiment, the cam 24 has the inner race 2
A configuration is employed in which the cam 24 rotates eccentrically by using an eccentric 4a. (Third Embodiment) The motor 1 in the third embodiment is
FIG. 3 shows a case in which it is assembled to the housing 8a. Second
In the embodiment, a configuration using a shaft that is not divided is used, but in the present embodiment, a configuration that uses a shaft that is divided into two parts is used. In addition,
Since the configuration of the motor 1 in the present embodiment is substantially the same as that of the first embodiment, only the differences from the first embodiment will be described.

As shown in FIG. 4, the shaft 17 is divided into two parts, and is composed of a first shaft 17a serving as the axis of the core 13 and the commutator 14, and a second shaft 17b serving as the axis of the cam 24. The first shaft 17a and the second shaft 17b are fastened at their respective ends to form one shaft 17. in this way,
When the shaft 17 is divided, the load on the second shaft 17b by the pump 5 can be prevented from being transmitted to the first shaft 17a. Specifically, the load generated by the pump 5 causes the second shaft 17b to bend. However, the deflection can be prevented from being transmitted to the first shaft 17a by dividing the shaft 17.
That is, the deflection is not transmitted to the core 13 and the like disposed on the first shaft 17a side, and the vibration of the motor 1 can be more effectively prevented.

The bearing of the shaft 17 thus divided will be described in detail. Both ends of the first shaft 17a are supported by a slide bearing 19 and a slide bearing 40. The sliding bearing 40 is fixed to the lid portion 21 and has a tapered shape such that the bearing surface (inner diameter) expands in the direction of the core 13. Further, the surface of the shaft 17 that comes into contact with the slide bearing 40 is formed in a tapered shape according to the shape of the slide bearing 40.

Both ends of the second shaft 17b are supported by ball bearings 41 and sliding bearings 42. The ball bearing 41 is disposed between the cam 24 and the sliding bearing 40, and has a stepped portion 8 provided in a concave portion of the first housing 8a.
It is locked by d so that it cannot move in the shaft axis direction. The slide bearing 42 is fixed by a concave portion formed in the first housing 8a.

Then, the slide bearing 19 and the slide bearing 3
The gap between the sliding bearing 19 and the sliding bearing 40 and the shaft 17 is eliminated when the sliding bearing 19 is screwed and fixed by making the surfaces of the bearings 0 tapered so as to spread in the direction of the core 13. Is available. On the other hand, the first shaft 17a and the second shaft 1
7b is a single shaft 17, and the second shaft 17b also moves in the axial direction of the shaft 17 with the movement of the first shaft 17a due to the screwing and fixing of the slide bearing 19. Therefore, the inner race 41 a of the ball bearing 41 moves in the axial direction of the shaft 17. At this time, the ball bearing 4
Since the first outer ring 41b is locked by the step 8d, the inner ring 41a and the outer ring 41b are pressed against the rolling elements 41c relatively in opposite directions, so that a gap in the ball bearing 41 can be eliminated.

As described above, the shaft 17 and the ball bearing 41
Since the gap between the motor 1 and the sliding bearings 19 and 40 is eliminated, the vibration of the motor 1 can be prevented in the same manner as in the above embodiment. Further, in the present embodiment, the shaft 17 is divided to prevent the deflection caused by the load of the pump 5 from being transmitted to the core 13 and the like, so that the vibration of the motor 1 can be more effectively prevented. .

(Other Embodiments) In the above embodiment, the positioning of the sliding bearing 19 is adjusted based on the rotational torque of the sliding bearing 19 when the screw is tightened. 12 (rotor 1
The current flowing in 5) may be used as the no-load current, and the positioning adjustment may be performed using the no-load current value as a trigger.

In the above embodiment, the slide bearing 19 is fixed to the window 10b by adhesive after the positioning adjustment.
By swaging a part of the motor yoke 10, the sliding bearing 1
9 may be swaged and fixed to the window 10b.

[Brief description of the drawings]

FIG. 1 is a half sectional view when a motor according to a first embodiment is assembled to a housing.

FIG. 2 is a diagram showing a rotational torque-load characteristic when a slide bearing is screwed to a window.

FIG. 3 is a half sectional view when a motor according to a second embodiment is assembled to a housing.

FIG. 4 is a half sectional view when a motor according to a third embodiment is assembled to a housing.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Motor, 8a ... 1st housing, 8b ... 2nd housing, 10 ... Motor yoke, 10b ... Window part, 11 ... Magnet, 12 ... Coil, 13 ... Core, 14 ... Commutator, 15 ... Rotor, 16 ... Brush , 17 ... shaft, 1
8 ... Ball bearing, 18a ... Inner ring, 18b ... Outer ring, 18c ...
Rolling element, 19: sliding bearing, 24: cam.

Claims (6)

[Claims] A rotor (15) and the rotor (15)
A motor (1) having a shaft (17) serving as a rotation axis of the motor; and an eccentric part (24) that rotates in an eccentric state with the rotation of the shaft (17). The pump (5) provided in the housing (8) is driven by the rotation of the brake fluid to suck and discharge the brake fluid to control the brake fluid pressure. The sliding bearing (19) is supported by at least one sliding bearing (19), and the bearing surface of the sliding bearing (19) and the surface of the shaft (17) that abuts the sliding bearing (19) are both included in the rotor (15). Brake fluid pressure control, wherein the sliding bearing (19) is movable in the direction of the rotor (15). Use actuator. 2. The shaft (17) is obtained by combining a divided first shaft (17a) and a second shaft (b) into one, and the first shaft (17a) is provided with a rotor (15). The actuator for brake fluid pressure control according to claim 1, wherein an eccentric part (24) is arranged on the second shaft (17b). 3. The motor (1) has a motor yoke (10) serving as a case of the motor, and the motor yoke (10) is provided with the sliding bearing (1).
9) is provided with a window (10b) into which the window (10b) can be inserted, and a contact surface between the window (10b) and the slide bearing (19) is formed in a screw shape. Brake fluid according to claim 1 or 2, characterized in that the sliding bearing (19) moves in the direction of the rotor (15) by screwing it into the window (10b). Pressure control actuator. 4. A method for positioning a sliding bearing in a brake hydraulic pressure control actuator according to claim 3, wherein said sliding bearing (19) is screwed into said window (10b) when said sliding bearing (19) is screwed. A positioning method for a slide bearing, wherein the positioning of the slide bearing (19) is adjusted based on the rotational torque of (19). 5. A method for positioning a slide bearing in a brake fluid pressure control actuator according to claim 3, wherein the rotor (15) is attached to the rotor (15) in a no-load state before screwing the slide bearing (19). A method for positioning a sliding bearing, wherein the positioning of the sliding bearing (19) is adjusted based on a current value of a flowing current. 6. The slide bearing (19) is fixed to the window (10b) after the positioning of the slide bearing (19) is adjusted.
3. The method for positioning a sliding bearing according to 1.).