JP2001263257A - Plunger pump structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plunger pump structure capable of restraining generation of sound vibration by restraining deflection of a camshaft even when pressurizing only delivery fluid pressure of a camshaft tip side plunger pump without largely increasing a cost and without deteriorating a vehicle mounting characteristic in a structure for juxtaposing a main plunger pump and a sub-plunger pump in the shaft direction of the camshaft. SOLUTION: This plunger pump structure is formed as a support structure for rotatably supporting the camshaft 3 by a first bearing 6 and a second bearing 9 respectively interposed between the bearings and a housing 1 in a motor 2 side position close to a first driving cam 7 for driving the main plunger pump 4 and a position between the first driving cam 7 and a second driving cam 8 for driving the sub-plunger pump 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plunger pump structure in a brake fluid pressure control device including a supercharging sub-plunger pump in addition to a main plunger pump.

[0002]

2. Description of the Related Art Conventionally, as a plunger pump structure in a brake fluid pressure control device provided with a sub-plunger pump for supercharging in addition to a main pump pump, for example, Japanese Unexamined Patent Application Publication No. 10-6954, “Pump Device and Brake Control Devices "are known. The plunger pump structure in this conventional example has a camshaft 1 driven by a motor 101 as shown in a sectional view of FIG.
02 provided on the housing 103 in a state of being opposed to each other vertically toward
Each plunger 105a, 10
5a, a pair of main plunger pumps (first plunger pumps) 105, 105 abutting against each other, the pair of main plunger pumps 105, 105 and the camshaft 10
The second drive cams 106 are provided on the housing 103 in a state where they are arranged in the axial direction of the camshaft 102 and vertically opposed to each other toward the camshaft 102.
And a pair of supercharging sub-plunger pumps (second plunger pumps) 107, 107 in which the tips of the plungers 107a, 107a abut on the cam surfaces of the cam shaft 102 from the first drive cam 104. A bearing 108 is provided between the motor 103 and the housing 103 at a position on the motor 101 side.
The structure was such that it was supported by rotation.

[0003]

However, in the conventional plunger pump structure, as described above,
Since the main plunger pumps 105, 105 and the sub-plunger pumps 107, 107 are driven by one motor 101 in a state of being juxtaposed in the axial direction of the camshaft 102, the following problems arise. there were. That is, in the brake fluid pressure control device having a control pressure sensor on the discharge side of the sub-plunger pumps 107, 107, the sub-plunger on the distal end side of the cam shaft 102 for checking the operation of the control pressure sensor. When control is performed such that only the discharge liquid pressure of the pumps 107, 107 is increased, the cam shaft 102 is in a cantilever state, and the bearing 108 and the sub-plunger pump 107,
Since the span between the second drive cam 106 for driving the drive shaft 107 and the second drive cam 106 is long, the amount of deflection of the cam shaft 102 is increased, and as a result, the sound vibration is increased.

[0004] In order to solve the above problems, for example, WO96 / 18816, "Piston pump"
As shown, there is disclosed a camshaft in which a tip end side of a camshaft is supported by a housing in addition to a motor side. However, since this conventional example has only one plunger pump in the axial direction,
Although there is no particular problem, as shown in FIG. 3, when applied to a structure in which the main plunger pumps 105, 105 and the sub-plunger pumps 107, 107 are juxtaposed in the axial direction of the cam shaft 102, the cam shaft The span between the bearing 109 for rotatably supporting the distal end side of the motor 102 and the bearing 108 for the motor 101 becomes longer, and both the driving cams 104 and 106 are eccentric from the axis of the cam shaft 102, and Since the bearings are usually incorporated in the two driving cams 104 and 106, the diameter of the camshaft 102 needs to be reduced toward the tip, so that the bending of the intermediate portion of the camshaft 102 during driving can be sufficiently reduced. The rigidity to control can no longer be secured,
In order to secure sufficient rigidity, the diameter of the entire camshaft 102 and the size of the motor 101 need to be increased.
In order to support the tip of the camshaft 102 with the bearing 109, it is necessary to increase the length of the camshaft 102 and the width of the housing 103 by that much, so that the mountability of the vehicle is deteriorated and the cost is increased. Will be invited.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems. In a structure in which two plunger pumps are juxtaposed in the axial direction of a camshaft, the cost and the vehicle mountability are greatly increased. Even when only the discharge pressure of the plunger pump at the tip of the camshaft is increased without causing deterioration, the plunger pump structure is capable of suppressing the flexure of the camshaft and thereby suppressing the generation of sound vibration. The purpose is to provide.

[0006]

In order to achieve the above-mentioned object, in the plunger pump structure according to the first aspect of the present invention, the plunger pump structure is provided on the housing so as to be vertically opposed to a cam shaft rotated and driven by a motor. A pair of first plunger pumps, each having a tip end of each plunger abutting against a cam surface of a first drive cam provided on the cam shaft, and a pair of the first plunger pumps and an axial direction of the cam shaft. And the tip of each plunger is brought into contact with the cam surface of a second drive cam provided on the housing and provided on the camshaft so as to face each other vertically toward the camshaft. A pair of second plunger pumps, wherein the first drive cam and the second drive cam each have a bearing incorporated therein. The first and second drive cams are rotatably supported by a first bearing and a second bearing interposed between the first drive cam and a position between the first drive cam and the second drive cam. The means have been.

In the plunger pump structure according to a second aspect, in the plunger pump structure according to the first aspect,
The means is configured so that the outer periphery of the first bearing is fitted and supported on the housing via the casing of the motor.

[0008] In the plunger pump structure according to the third aspect, in the plunger pump structure according to the first aspect,
The discharge pressure of the second plunger pump is configured to be lower than the discharge pressure of the first plunger pump.

[0009]

In the plunger pump structure according to the first aspect of the present invention, as described above, the cam shaft is positioned closer to the motor than the first drive cam and the first drive cam and the second drive cam are connected to each other.
By being rotatably supported by a first bearing and a second bearing interposed between the housing and a position between the drive cam and the drive cam, only the discharge pressure of the plunger pump at the tip end of the camshaft is increased. Also in this case, the camshaft is suppressed by the second bearing,
This makes it possible to suppress the generation of sound vibration.
Further, by providing the second bearing between the first driving cam and the second driving cam, it is not necessary to increase the length of the cam shaft or increase the diameter in order to increase the rigidity, and therefore, the cost is greatly increased. There is no increase in the mountability and deterioration of the vehicle mountability.

In the plunger pump structure according to the second aspect, as described above, the outer periphery of the first bearing is configured to be fitted and supported on the housing via the casing of the motor, so that the bearing provided on the motor is provided. As well as being able to be used as the first bearing, the motor casing can be fixed to the housing at the same time, whereby the cost can be reduced and the assembling workability can be improved.

In the plunger pump structure according to the third aspect, as described above, the discharge pressure of the second plunger pump is configured to be smaller than the discharge pressure of the first plunger pump, so that the effect of suppressing sound vibration is further improved. Thus, the rigidity of the camshaft can be set low.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a sectional view showing a plunger pump structure according to an embodiment of the present invention. In the drawing, reference numeral 1 denotes a housing, 2 denotes a motor, 3 denotes a camshaft, 4 and 4 denote a main plunger pump (first plunger pump), 5 and 5 are sub-plunger pumps for supercharging (second plunger pumps)
It is.

A mounting hole 11 for inserting and supporting the camshaft 3 is formed on one side surface of the housing 1, and a casing (described later) of the motor 2 is formed on an opening edge side of the mounting hole 11. Projection (motor casing) 22
Is formed with a large-diameter hole portion 12 for supporting mounting.

That is, the camshaft 3 is formed integrally with a drive shaft in the motor 2 and the surface of the motor 2 on which the casing 21 is attached to the housing 1 is formed in a concentric manner on the outer periphery of the camshaft 3. A casing protrusion 22 that can be mounted is formed in the radial hole portion 12 and a first bearing 6 that rotatably supports the cam shaft 3 is mounted in the casing protrusion 22.

The motor 2 has a camshaft 3 formed integrally with a drive shaft thereof inserted into the mounting hole 11 of the housing 1 and a casing projection 22 mounted and supported in the large-diameter hole 12. Thus, mounting and fixing to the housing 1 are performed. That is, the motor 2 and the camshaft 3 are assembled in a state where the outer periphery of the first bearing 6 is fitted and supported in the large-diameter hole 12 of the housing 1 via the casing protrusion 22 of the motor 2.

The main plunger pumps 4, 4 are pressurizing pumps for pressurizing and supplying brake fluid in a reservoir tank (not shown) to the brake hydraulic circuit side, and are perpendicular to the camshaft 3. The first drive cam 7 provided on the camshaft 3 is provided in the housing 1 in a state where the front ends of the plungers 41 abut on the cam surface.

The supercharging sub-plunger pumps 5, 5 are supercharging pumps for supplying brake fluid from the reservoir tank on the master cylinder side (not shown) to the main plunger pumps 4, 4. The main plunger pumps 4, 4 are provided in the housing 1 in a state where they are arranged in the axial direction of the camshaft 3, respectively, and are vertically opposed to each other toward the camshaft 3. The plungers 51 are provided in a state where the tips of the plungers 51 abut on the cam surface of the second drive cam 8 provided on the side.

The first drive cam 7 and the second drive cam 7
The drive cam 8 is formed by attaching bearings 71 and 81 to an eccentric shaft formed on the camshaft 3. In the figures, 42 and 52 are suction valves,
Reference numerals 43 and 53 indicate discharge valves.

As described above, the cam shaft 3 is provided with the first bearing 6 at a position closer to the motor 2 than the first drive cam 7.
And is rotatably supported by the housing 1 at a position between the first drive cam 7 and the second drive cam 8 by a second bearing 9 interposed between the housing 1 and the first drive cam 7. It has a structure.

In the plunger pump structure according to the embodiment of the present invention, as described above, the cam shaft 3 is positioned between the first drive cam 7 and the motor 2 and between the first drive cam 7 and the second drive cam 8. At a position, the first bearing 6 and the second bearing 9 interposed between the housing 1 and the first bearing 6 rotatably support the support structure,
Even when only the discharge hydraulic pressure of the sub-plunger pumps 5, 5 on the tip side of the camshaft 3 is pressurized, it is possible to suppress the bending of the camshaft 3 by the second bearing 9, thereby suppressing the generation of sound vibration. The effect that it becomes possible is obtained.

The second bearing 9 is connected to the first drive cam 7.
And the second drive cam 8, there is no need to increase the length of the camshaft 3 or to increase the diameter in order to increase the rigidity. An effect is obtained that it is possible to suppress the generation of sound vibration without inviting.

The outer periphery of the first bearing 6 is
Is configured to be fitted and supported on the housing 1 via the casing protrusion 22 of the motor 2, the bearing provided on the motor 2 side can be used as the first bearing 6, and the motor casing 21 for the housing 1 can be used. Can be fixed at the same time,
The effect is obtained that the cost can be reduced and the assembling workability can be improved.

The sub-plunger pumps 5, 5 having a smaller discharge pressure than the main plunger pumps 4, 4 are arranged on the tip side of the camshaft 3, thereby further improving the effect of suppressing sound vibration. Or the rigidity of the camshaft 3 can be set low.

Although the preferred embodiments of the present invention have been described in detail with reference to the drawings, the specific configuration is not limited to these preferred embodiments, and design changes may be made without departing from the scope of the present invention. The present invention is also included in the present invention.

For example, in the embodiment of the present invention, the outer periphery of the first bearing 6 is supported by the housing 1 through the casing protrusion 22 of the motor 2. However, the outer periphery of the first bearing 6 is directly supported by the housing 1 without the intervention of the casing. You may make it do.

In the embodiment of the present invention, the sub-plunger pumps 5, 5 having a smaller discharge pressure than the main plunger pumps 4, 4 are arranged on the tip side of the camshaft 3, but they are arranged in reverse. You may make it do.

[0027]

As described above, according to the first aspect of the present invention,
In the plunger pump structure described in the above, the cam surface of the first drive cam provided on the housing in a state of being vertically opposed to the cam shaft rotated and driven by the motor and provided on the cam shaft A pair of first plunger pumps, the ends of which are in contact with each other, and a state in which the pair of first plunger pumps and the pair of first plunger pumps are juxtaposed in the axial direction of the camshaft and face each other vertically toward the camshaft; A pair of second plunger pumps, each of which has a tip of each plunger abutted against a cam surface of a second drive cam provided on the camshaft and provided on the camshaft, wherein the first drive cam and In a plunger pump in which a bearing is incorporated in each of the second drive cams, the camshaft is positioned closer to the motor than the first drive cam and is connected to the first drive cam. By means rotatably supported by the first bearing and the second bearing interposed between the housing and the housing at a position between the two drive cams, the discharge liquid of the plunger pump at the tip end of the camshaft is provided. Even when only the pressure is applied, the camshaft is suppressed by the second bearing, whereby the effect of suppressing the generation of sound vibration can be obtained.

By providing the second bearing between the first drive cam and the second drive cam, it is not necessary to increase the length of the cam shaft or increase the diameter in order to increase the rigidity.
Therefore, it is possible to suppress the occurrence of sound vibration without significantly increasing the cost and deteriorating the mountability of the vehicle.

In the plunger pump structure according to the second aspect, in the plunger pump structure according to the first aspect,
The first bearing is configured such that the outer periphery of the first bearing is fitted and supported in the housing via the casing of the motor, so that the bearing provided in the motor can be used as the first bearing.
As well as being able to be used as a bearing, the motor casing can be fixed to the housing at the same time, so that the cost can be reduced and the assembling workability can be improved.

In the plunger pump structure according to the third aspect, in the plunger pump structure according to the first aspect,
Since the discharge pressure of the second plunger pump is configured to be smaller than the discharge pressure of the first plunger pump, the effect of suppressing sound vibration can be further increased, or the camshaft can be improved. Can be set low.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a plunger pump structure according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a conventional plunger pump structure.

FIG. 3 is a sectional view showing a conventional plunger pump structure.

[Explanation of symbols]

 Reference Signs List 1 housing 2 motor 3 camshaft 4 main plunger pump (first plunger pump) 5 sub-plunger pump (second plunger pump) 6 first bearing 7 first driving cam 8 second driving cam 9 second bearing 11 mounting hole 12 large Diameter hole 21 Casing 22 Casing protrusion (motor casing) 41 Plunger 42 Suction valve 43 Discharge valve 51 Plunger 52 Suction valve 53 Discharge valve 71 Bearing 81 Bearing

Claims (3)

[Claims] An end of each plunger is provided to a cam surface of a first drive cam provided on a housing so as to be vertically opposed to a cam shaft rotated and driven by a motor. A pair of first plunger pumps that are in contact with each other, and a pair of the first plunger pumps are provided in the housing so as to be juxtaposed in the axial direction of the camshaft and perpendicularly opposed to each other toward the camshaft. A pair of second plunger pumps, wherein the tip of each plunger abuts against a cam surface of a second drive cam provided on the camshaft;
A plunger pump in which bearings are respectively incorporated in the first drive cam and the second drive cam, wherein the camshaft is located on the motor side of the first drive cam and the first drive cam and the second drive A plunger pump structure characterized by being rotatably supported by a first bearing and a second bearing interposed between the housing and a position between the cam and the cam. 2. A plunger pump structure according to claim 1, wherein an outer periphery of said first bearing is fitted and supported on a housing via a casing of said motor. 3. The plunger pump structure according to claim 1, wherein the discharge pressure of the second plunger pump is lower than the discharge pressure of the first plunger pump.