JP2001048001A - Master cylinder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To arrange a discharge port for supplying a hydraulic pressure generated within a sleeve to the outside at an arbitrary position by forming a flow passage communicated with the inside through a hole part of an upper part of the sleeve along a part of a peripheral direction of the sleeve and making the discharge port communicate with the flow passage, on an outer peripheral side of the sleeve. SOLUTION: In a state that a sleeve 10 of a cylinder body is stored into a housing, an annular flow passage 26 is formed by a groove part 25 formed on an outer peripheral part of the sleeve 10 and an inner peripheral surface of a front housing 22. The annular flow passage 26 is communicated with the inside of the sleeve 10 through a hole part 24 formed on an upper part of the sleeve 10. A discharge port 11 is arranged so as to be communicated with the annular flow passage 26 on a lower side of the front housing 22. The discharge port 11 is communicated with the sleeve 10 through the annular flow passage 26 and the hole part 24. As a result, the discharge port 11 can be arbitrarily arranged within a prescribed range in the peripheral direction of the cylinder body.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a master cylinder such as a hydraulic brake master cylinder or a hydraulic clutch master cylinder mounted on a vehicle such as an automobile.

[0002]

2. Description of the Related Art A conventionally known master cylinder typically includes a cylindrical sleeve opened at both ends and a sliding member slidably fitted in the sleeve. And a reservoir tank mounted on the cylinder body and storing a pressure medium. In the master cylinder having such a configuration, a pressure medium is supplied from the reservoir tank along with the driving of the sliding member slidably inserted into the sleeve, and hydraulic pressure is supplied into the sleeve of the cylinder body. A discharge port communicating with the inside of the sleeve is provided at a predetermined position of the housing in order to supply the generated hydraulic pressure toward a predetermined external device to be used.

[0003]

Generally, in a master cylinder, it is necessary to appropriately discharge air from the cylinder body in order to prevent accumulation of the air that has entered the cylinder body. For convenience, it is common to arrange the discharge port above the cylinder main body, and to discharge air moved upward in the cylinder main body with the supply of hydraulic pressure, thereby discharging air from the cylinder main body. It is a target. However, when the discharge ports are arranged in this manner, various components are concentrated on the upper side of the cylinder body, and there is a concern that the structure may be complicated at that portion. This is because, as a general structure of the master cylinder, an assembly structure for the reservoir tank is provided above the cylinder body, and a pressure medium from the reservoir tank to the discharge port is provided near the assembly structure. Is formed. As described above, various components are concentrated in the local area, and as a result of each component being incorporated into the cylinder body, the radial size of the cylinder body increases.

[0004] Further, as described above, a cylinder body made of a cast product such as aluminum (Al) die cast or Al alloy die cast, and finished by machining mainly into a final shape is manufactured as described above. When the discharge port is arranged, if the structure becomes complicated on the upper side of the cylinder body, machining of the casting material becomes more complicated and high precision is required. It is very disadvantageous in reducing the amount of light. Particularly, in a master cylinder (a so-called plunger-type master cylinder) having a structure in which a seal member is fitted and fixed to the inner periphery of a sleeve and a plunger is driven in the sleeve, the size of the cylinder body in the longitudinal direction is reduced. Although advantageous in view of the above, the size in the radial direction is relatively large and the structure is said to be relatively complicated, and there is much room for reconsideration of the structure as described above.

Accordingly, the present invention has been made in view of the above technical problem, and a discharge port for supplying a hydraulic pressure generated in a sleeve to the outside is located at an arbitrary position within a predetermined range in a circumferential direction of a cylinder body. An object is to provide a master cylinder having a structure that can be arranged.

[0006]

For this reason, the invention according to claim 1 of the present application (hereinafter referred to as the first invention) has a cylindrical sleeve opened at both ends and slidably fitted in the sleeve. A cylinder body having a sliding member to be inserted therein and a housing for accommodating the sleeve, and a reservoir tank for storing a pressure medium supplied to the cylinder body; In the master cylinder in which the supply outlet is provided in the housing,
On the outer peripheral side of the sleeve, a flow path communicating with the inside of the sleeve through a hole provided in the upper part of the sleeve is formed along at least a part of the sleeve in the circumferential direction, and the discharge port is The position is set so as to communicate with the flow path.

Further, the invention according to claim 2 of the present application (hereinafter referred to as “the invention”)
The second invention) is characterized in that engaging means are provided on the outer peripheral surface of the sleeve and the inner peripheral surface of the housing so as to engage with each other to relatively position the sleeve and the housing. It was done.

Further, the invention according to claim 3 of the present application (hereinafter referred to as “the invention”)
A third aspect of the present invention is characterized in that a plurality of the holes for communicating the flow path with the inside of the sleeve are provided at predetermined intervals in a circumferential direction of the sleeve.

Further, the invention according to claim 4 of the present application (hereinafter, referred to as a fourth invention) is characterized in that the housing is formed by bending a steel plate material.

[0010]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a partial vertical cross-sectional explanatory view of a hydraulic brake master cylinder provided in a brake system of an automobile, for example. Embodiment 1
The master cylinder 1 according to (1) has a structure in which a plurality of seal members made of an elastic material are fitted into the inner periphery of a cylindrical body and a sliding member such as a plunger is driven in the cylindrical body (a so-called plunger-type master cylinder). As a basic component, a cylinder body 2 in which a substantially cylindrical sleeve 10 opened at both ends is housed in a housing 20.
And a reservoir tank 3 attached to the upper side of the cylinder body 2 for storing a pressure medium (oil for hydraulic pressure). The sleeve 10 of the cylinder body 2 includes a pair of plunger pieces. Plunger 6 is slidably fitted.

The plunger 6 connects the first and second plunger pieces 6A and 6B arranged in series with a connecting member 7.
A and the coupling member 8A are configured to be engaged with each other. In the master cylinder 1, an annular seal cup 15, 1 made of an elastic material is provided on the inner periphery of the sleeve 10.
6, 17 and 18 are fitted therein, and each of the plunger pieces 6A and 6B slides within the sleeve 10 so that these seal cups 15, 16 and 1 are respectively fitted.
7 and 18 in liquid tight contact. In the cylinder body 2, the first and second plunger pieces 6 </ b> A and 6 </ b> B form a first hydraulic chamber 19 together with the inner periphery of the sleeve 10.

Further, in the first embodiment, a housing 20, which is formed by bending a steel plate material, is employed as a housing constituting the outer shape of the cylinder body 2, and the sleeve 10 is housed in the housing 20. I have. The housing 20 is configured by combining a rear housing 21 and a front housing 22 that are divided into front and rear portions in the longitudinal direction of the cylinder body 2. One end of the housing 20 is combined with the other so as to house the sleeve 10. The first plunger piece 6A is inserted through the first plunger piece 6A. On the other hand, on the other end side, the sleeve 10 is closed facing the front end of the sleeve 10,
A second hydraulic chamber 29 is formed together with one end of the second plunger piece 6B fitted in the sleeve 10 and the inner periphery of the sleeve 10. In addition, in the above "bend molding",
This includes not only mechanical pressing such as bending, bending, or drawing, but also hydraulic forming.

When using the master cylinder 1,
A reservoir tank 3 for storing a pressure medium is attached to the upper side of the cylinder body 2. For this reason, the reservoir tank 3 is arranged along the longitudinal direction of the cylinder body 2 on the upper part of the housing 20 (that is, the front housing 22). Holes 36A and 36B are provided.
Bosses 37A and 37B for mounting the reservoir tank 3 are fixed by welding, for example, corresponding to 36B. In the first embodiment, the plunger 6 in which the cylinder body 2 is inserted into the sleeve 10 is used.
Before being mounted on an actuator (not shown) that can drive the
The rear housing 21 and the front housing 22 are temporarily fixed with a predetermined pin member 28 in a state where they are combined with each other. In the vicinity of the joint between the rear housing 21 and the front housing 22, an annular packing member 14 is fitted between the two, so that leakage of fluid to the outside is reliably prevented.

In the master cylinder 1 having the basic configuration as described above, one open end side of the sleeve 10 (FIG. 1).
The first plunger piece 6 located on the right end side
A is connected to a brake pedal (not shown) via, for example, a rod member or the like (not shown), and the first plunger piece 6A is depressed on its brake pedal, thereby causing the spring 9A (first spring) to move. It is driven to the left in FIG. 1 against the urging force. Along with this, the second plunger piece 6B is also driven to the left in FIG. 1 via the first spring 9A against the urging force of the spring 9B (second spring). A hydraulic pressure is generated in the sleeve 10.

The hydraulic pressure generated in the sleeve 10 through the outlet 11 through an outlet plug 12 and a hydraulic pipe (not shown) passes through a predetermined external device (ie, a wheel cylinder of each wheel: not shown). ). The basic configuration and operation of the master cylinder 1 described above are the same as those well known in the related art, and are not directly related to the gist of the present invention. Illustration is omitted.

Next, a description will be given of a structure in which the discharge port 11 for supplying the hydraulic pressure generated in the cylinder body 2 to the outside can be arbitrarily arranged in the circumferential direction of the cylinder body 2.
In the first embodiment, a substantially vertical hole 24 communicating with the inside of the sleeve 10 is provided at an upper portion of the sleeve 10 housed in the cylinder body 2. Further, a groove 25 having a predetermined depth is formed in the outer peripheral portion of the sleeve 10 by stepping down the surface of the sleeve along the circumferential direction. The groove 25 is formed through the hole 24. 10 communicates with the inside. FIG.
FIG. 4 is an explanatory longitudinal sectional view of the cylinder body 2 taken along an X-ray.
As can be clearly understood from this figure, when the sleeve 10 is housed in the housing 20, the groove 25 formed on the outer periphery of the sleeve 10 and the front housing 2
2 and an inner peripheral surface of the flow path 26 (hereinafter, substantially annular in cross section).
(Referred to as an annular flow path). The annular flow path 26 communicates with the inside of the sleeve 10 through a hole 24 formed in an upper part of the sleeve 10.

Further, in the first embodiment, the discharge port 11 is disposed below the front housing 22 so as to communicate with the annular flow path 26. This outlet 1
1 communicates with the inside of the sleeve 10 via the annular flow path 26 and the hole 24. An outlet plug 12 is fixed to the side surface of the housing 22 corresponding to the discharge port 11 by, for example, welding. As shown in FIG. 1, a sealing member 38 such as an O-ring is fitted on both sides of the groove 25, and the sealing member 38 is
By making a liquid-tight contact with the inner peripheral surface of the second member 2, leakage of the fluid from the annular flow path 26 to the outside is reliably prevented.

In the cylinder body 2 having such a structure,
The hydraulic pressure generated in the sleeve 10 (that is, the first hydraulic chamber 19) is first sent to the annular flow path 26 through the hole 24 of the sleeve 10, Is supplied from a discharge port 11 provided on the lower side to a predetermined external device. When air enters the sleeve 10, the air is sent to the annular flow path 26 through the hole 24 along with the above-described hydraulic pressure supply, and the discharge port is discharged through the annular flow path 26. It is discharged to the outside from 11. As a result, air accumulation in the cylinder body 2 is prevented.

As described above, by forming the annular flow path 26 communicating with the inside of the sleeve 10 along the circumferential direction of the sleeve 10, the air flows in the annular flow along with the supply of the hydraulic pressure from inside the cylinder body 2. Since the discharge port 11 can be discharged through the passage 26, the discharge port 11 can be arranged at an arbitrary position in the circumferential direction of the cylinder body 2 without being limited to the upper side of the cylinder body 2. Thereby, for example, the ejection port 11
When the upper part of the cylinder body 2 is removed, for example, when the upper part of the cylinder body 2 is
The structure is simplified on the upper side of the cylinder body.
In the above, the flow path for the pressure medium from the reservoir tank 3 (see FIG. 1) to the discharge port 11 can be designed while reducing the size of the product in the radial direction.

In the first embodiment, the sleeve 1
0 is used as a housing for accommodating zero, a housing 20 formed by bending a steel plate material is employed.
The thickness of the housing 20 can be reduced.
In manufacturing the housing 20, relatively stable quality can be ensured. This makes it possible to reduce the size and weight of the product, and further reduce the manufacturing cost. Further, in this case, the outlet plug 12 is separately attached to the discharge port 11 provided in the front housing 22 by, for example, welding, and compared with a case where a conventional general casting mold housing is adopted. Since it is not necessary to manufacture a casting mold of the outlet plug for each discharge port, the housing 20 can be manufactured more efficiently, and the manufacturing cost can be reduced.

FIG. 3 is an explanatory longitudinal sectional view of the cylinder body taken along the line YY in FIG. In the first embodiment, a recess 27 that is recessed inward in the radial direction of the housing 21 is formed in a part of the upper side surface of the rear housing 21 along the circumferential direction, while the outer circumferential surface of the sleeve 10 is A receiving groove 3 having a predetermined depth is formed in a portion facing the concave portion 27.
1 is formed. These recesses 27 and receiving grooves 31
Are engaged with each other in a state where the sleeve 10 is fitted into the rear housing 21, whereby the sleeve 10
And the rear housing 21 is relatively positioned in the circumferential direction.

As described above, by providing the concave portion 27 and the receiving groove 31 which are engaged with each other on the outer peripheral surface of the sleeve 10 and the inner peripheral surface of the rear housing 21, respectively.
The sleeve 10 and the rear housing 21 are relatively positioned in the circumferential direction, so that accidental rotation of the sleeve 10 in the rear housing 21 can be restricted. In this case, when assembling the sleeve 10 and the rear housing 21, a flow path for a pressure medium from the mounting portion of the reservoir tank 3 in the cylinder body 2 to the first hydraulic chamber 19 is formed. In addition, both can be easily positioned.

FIG. 4 is an explanatory longitudinal sectional view similar to FIG. 2, showing a modified example of the sleeve 10 and the front housing 22 incorporated in the cylinder body 2. As shown in FIG. In the above-described first embodiment, only one hole 24 that connects the first hydraulic chamber 19 and the annular flow path 26 in the sleeve 10 is formed in the upper part of the sleeve 10. However, the present invention is not limited to this. Without being carried out, as shown in FIG.
A hole 24 ′ communicating between an annular flow path 26 ′ formed between the groove 25 ′ of 0 ′ and the inner peripheral surface of the front housing 22 ′ and the inside of the sleeve 10 ′ is formed in the sleeve 10 ′.
A plurality may be provided along the radial direction of the sleeve 10 ′ at predetermined intervals in the circumferential direction of the sleeve 10 ′.

With such a structure, the air is efficiently discharged from the cylinder body 2, and the accumulation of air in the cylinder body 2 is more reliably prevented. In addition, when this structure is used, the discharge port 11 ′ formed in the front housing 22 ′ is required to reliably discharge air.
Preferably, it is formed closer to the upper side of the front housing 22 '. This is the same for the outlet plug 12 'attached to the outer periphery of the front housing 22' corresponding to the discharge port 11 '.

Next, a master cylinder according to a second embodiment of the present invention will be described. FIG. 5 is an explanatory longitudinal sectional view showing the master cylinder partially cut away.
In the master cylinder 40, for example, aluminum (Al) is used as a housing forming the outer shape of the cylinder body 42.
A housing 60 is used which is manufactured by finishing a cast product such as a die cast or an Al alloy die cast into a final shape mainly by machining. The master cylinder 40 has a substantially cylindrical sleeve 50 opened at both ends as in the first embodiment.
And a reservoir tank 43 attached to the upper side of the cylinder body 42 for storing the pressure medium supplied to the cylinder body 42. , Plungers 46 composed of first and second plunger pieces 46A and 46B are arranged in series and slidably fitted. Further, in the cylinder body 42, the first and second plunger pieces 46 fitted therein are inserted.
A, 46B and the inner periphery of the sleeve 50 form a first hydraulic chamber 59, while one end of the second plunger piece 46B, the housing 60 and the sleeve closed to face the end. A second hydraulic chamber 69 is formed by the inner periphery of 50.

In the second embodiment, as in the first embodiment, a sleeve 5
A substantially vertical hole 74 communicating with the inside of the hole 0 is provided. Further, a groove 75 having a predetermined depth is formed in the outer peripheral portion of the sleeve 50 by lowering the surface of the sleeve along the circumferential direction. The groove 75 is formed through a hole 74 formed in the upper part of the sleeve 50.
It communicates with the inside. FIG. 6 is an explanatory longitudinal sectional view taken along the line ZZ in FIG. As can be clearly understood from this figure, a groove 75 formed on the outer peripheral portion of the sleeve 50 in a state where the sleeve 50 is housed in the housing 60.
The inner peripheral surface of the housing 60 forms a substantially annular flow path 76 in a sectional view. This annular flow path 76
It communicates with the inside of the sleeve 50 (that is, the first hydraulic chamber 59) via a hole 74 formed on the upper side of the sleeve 50.

Further, in the second embodiment, the discharge port 51 is arranged below the housing 60 so as to communicate with the annular flow path 76 in the longitudinal direction thereof. The discharge port 51 is connected to the annular channel 76 and the hole 74.
Through the sleeve 50. In addition,
In the casting housing 60, an outlet plug 52 is formed integrally with the discharge port 51. Also,
As shown in FIG. 5, a sealing member 68 such as an O-ring is fitted on both sides of the groove 75 in the same manner as in the first embodiment, and is liquid-tight with respect to the inner peripheral surface of the housing 60. In contact.

In such a structure, an annular flow passage 76 communicating with the inside of the sleeve 50 is formed in the outer peripheral portion of the sleeve 50 along the circumferential direction, and the air is annularly supplied with the supply of the hydraulic pressure from inside the cylinder body 42. The discharge port 51 can be disposed at any position in the circumferential direction of the cylinder body 42 without being limited to the upper side of the cylinder body 42 because the discharge port 51 can be discharged through the flow path 76. Thus, for example, when the discharge port 51 is disposed below the cylinder body 42, the configuration is simplified on the upper side of the cylinder body 42, and as a result, the cylinder body 42 has a small size in terms of the radial size of the product. Thus, it is possible to design a flow path for the pressure medium from the reservoir tank 43 (see FIG. 5) to the discharge port 51 while achieving the desired structure.

The present invention is not limited to the illustrated embodiment, and it goes without saying that various improvements and design changes can be made without departing from the spirit of the present invention. For example, in the above-described embodiment, the flow path in the outer peripheral portion of the sleeve is formed in an annular shape. However, the present invention is not limited to this. As long as the sleeve communicates with the inside of the sleeve via the hole, it may be formed only in a part of the sleeve in the circumferential direction. With such a structure, the discharge ports can be arranged arbitrarily within a predetermined range in the circumferential direction of the cylinder body (that is, within a range where the flow path is formed).

[0030]

According to the first aspect of the present invention, at the outer peripheral side of the sleeve, the flow path communicating with the inside of the sleeve through the hole provided in the upper part of the sleeve is formed at least in the circumferential direction of the sleeve. By forming along the part, the air can be discharged through the above-mentioned flow path with the supply of the hydraulic pressure from inside the cylinder body, and in this structure, the air is not limited to the upper side of the cylinder body, The discharge ports can be arbitrarily arranged within a predetermined range in the circumferential direction.
Thus, when the discharge port is disposed with the upper side of the cylinder body removed, the configuration is simplified on the upper side of the cylinder body, and as a result, the cylinder body is reduced in size in terms of the radial size of the product. Thus, a flow path for the pressure medium from the reservoir tank to the discharge port can be designed.

According to the second aspect of the present invention, the outer peripheral surface of the sleeve and the inner peripheral surface of the housing are provided with engaging means for engaging each other to position the sleeve and the housing relatively. Therefore, after the sleeve and the housing are assembled, accidental rotation of the sleeve within the housing can be restricted. Further, in this case, when assembling the sleeve and the housing, the positioning of the sleeve and the housing can be easily performed in forming the flow path for the pressure medium in the cylinder body.

Further, according to the third aspect of the present invention, since the plurality of holes for communicating the flow path with the inside of the sleeve are provided at predetermined intervals in the circumferential direction of the sleeve, the cylinder is provided with a plurality of holes. Air can be efficiently discharged from the main body, and air accumulation in the cylinder body can be more reliably prevented.

Further, according to the fourth invention of the present application,
Since the housing is formed by bending a steel plate material, the thickness of the housing can be reduced, and relatively stable quality can be ensured in manufacturing the housing. This makes it possible to reduce the size and weight of the product, and further reduce the manufacturing cost.

[Brief description of the drawings]

FIG. 1 is an explanatory longitudinal sectional view showing an internal structure of a master cylinder according to Embodiment 1 of the present invention.

FIG. 2 is an explanatory longitudinal sectional view of the cylinder body taken along line XX in FIG. 1;

FIG. 3 is an explanatory longitudinal sectional view of the cylinder body taken along line YY in FIG. 1;

FIG. 4 is a longitudinal sectional view similar to FIG. 2, showing a modified example of the sleeve incorporated in the cylinder body.

FIG. 5 is an explanatory longitudinal sectional view showing an internal structure of a master cylinder according to Embodiment 2 of the present invention.

6 is an explanatory longitudinal sectional view of the cylinder body taken along the line ZZ in FIG. 5;

[Explanation of symbols]

 1, 40 master cylinder 2, 42 cylinder body 3, 43 reservoir tank 6, 46 plunger 10, 50 sleeve 11, 51 discharge port 20, 60 housing 24, 74 hole 25, 75 groove 26, 76 ... flow path 27 ... recess 31 ... receiving groove

Claims (4)

[Claims] 1. A cylinder body having a cylindrical sleeve opened at both ends, a sliding member slidably fitted in the sleeve, and a housing for accommodating the sleeve, and a cylinder body supplied to the cylinder body. A reservoir tank for storing a pressure medium, and a discharge port for supplying the hydraulic pressure generated in the sleeve to the outside is provided in the housing. A flow path communicating with the inside of the sleeve through a hole provided at an upper portion is formed along at least a part of a circumferential direction of the sleeve, and a position is set such that the discharge port communicates with the flow path. A master cylinder characterized by being made. 2. An outer peripheral surface of the sleeve and an inner peripheral surface of the housing are provided with engaging means which can engage with each other to relatively position the sleeve and the housing. 1. The master cylinder according to 1. 3. The method according to claim 1, wherein the hole for communicating the flow path with the inside of the sleeve is provided at a predetermined interval in a circumferential direction of the sleeve.
The master cylinder according to claim 1, wherein a plurality of the master cylinders are provided. 4. The master cylinder according to claim 1, wherein the housing is formed by bending a steel plate material.