JPS6143643Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an air bleed device for a brake circuit in a hydraulic brake used in a two-wheeled vehicle or the like.

Conventionally, when the brake pedal is pressed, hydraulic pressure is generated in the master cylinder, which strongly pushes the piston of the wheel cylinder to perform braking.In hydraulic brakes, air is removed from the brake oil circuit during assembly and oil replacement. This was accomplished by forming an independent port in the fuselage at the end of the circuit, and operating an air breather (a type of plug) attached to the port opening.

However, this method had the drawback of complicating the machining of the port group in the fuselage, including the brake oil inlet port, significantly impairing machinability and increasing costs.

The present invention has been proposed in view of the above, and an object of the present invention is to provide an air bleed device that can reliably bleed air from a brake circuit with a simple structure by using brake pipe mounting bolts. With the goal.

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIGS. 1 to 4 show examples in which the present invention is applied to a shock absorber for two-wheeled vehicles that senses brake oil pressure and changes the damping force.

In the figure, 1 is an outer tube connected to the axle side, and 2 is a hollow pipe installed vertically at the bottom of the outer tube.

An inner tube (not shown) connected to the vehicle body side is slidably inserted into the outer tube 1, and an annular piston fixed to the tip thereof is oil-tight between the inner circumferential surface of the outer tube 1 and the outer circumferential surface of the hollow pipe 2. It slides into contact with the piston, forming an oil chamber on the top and bottom surfaces of the piston. In the figure, A indicates the oil chamber which is at high pressure during pressure side operation.

A valve case 4 is attached to the bottom of the outer circumference of the outer tube 1, and a passage 6 is provided through which a relief valve 5 housed in the valve case 4 communicates with the oil chamber A.
It is interposed to open and close the connection between the hollow pipe 2 and the passage 7 that communicates with the internal oil reservoir chamber B.

The spring set load of the relief valve 5 is designed to increase or decrease depending on the braking force.

That is, the set spring 8 of the relief valve 5
is brought into pressure contact with a piston 10 which is inserted into a conduit 9 through which a part of the brake oil is guided and which responds to a brake pressure proportional to the braking force, and as the brake pressure increases, the piston 10 is moved toward the set spring 8 side. The set load is increased by moving it.

Therefore, with this shock absorber, during braking, the hydraulic fluid escaping from the shrinking oil chamber A to the oil reservoir chamber B can be regulated according to the braking force, effectively preventing the shock absorber (front fork) from sinking. In addition to being able to suppress
If the internal pressure of oil chamber A increases due to factors other than braking,
The relief valve 5 is unbalanced with the load of the spring 8, and the relief valve 5 opens in response to this increase in internal pressure, so even if an impact is received from the road surface during braking, the impact can be immediately alleviated. can.

In this invention, the other end ring portion 11A of the brake pipe 11, one end of which is connected to the master cylinder or the like, is inserted into the first bolt 12 and attached to the conduit 9.

This first bolt also has an air bleed device.

That is, as shown in FIG. 2, the first bolt 12 has an annular groove 13 formed on its outer periphery that communicates with the brake pipe 11, and this groove 13.
A through hole 14 communicating with the conduit 9 is formed longitudinally inside the shaft of the bolt 12.

Further, a through hole 15 for air bleeding passes through the bolt 12 on the axis thereof, and the through hole 15 is a stepped passage consisting of a small diameter through hole 15a and a large diameter through hole 15b.

A second bolt 16 for air bleeding is screwed into the large diameter through hole 15b, and by moving the second bolt 16 back and forth in the axial direction, the air bleeding hole 15
(Small diameter through hole 15a) communicates with and blocks the outside.

That is, the tip end 16a of the second bolt 16 is formed into a conical shape, and this tapered surface forms the stepped part 1 of the through hole 15.
By using 5c as a valve seat and moving them toward and away from each other, the small diameter through hole 15a and the large diameter through hole 15b communicate with each other.

The through hole 1 is also located on the axis of the second bolt 16.
7 passes through the bolt, and its inner end is bent in the radial direction near the tip 16a and opens to the bolt outer circumferential surface 18.

The through hole 14 is formed by chamfering a portion of the outer circumference of the shaft portion of the first bolt 12 as shown in FIGS. 3 and 4.
a (Figure 3) or slit 14b
(Fig. 4) may also be formed.

To bleed air during oil changes, etc., loosen the second bolt 16 and remove the conical tip 16.
If a is separated from the stepped portion 15c of the first bolt 12, the through hole 15a of the first bolt 12 will communicate with the outside via the second bolt 16, and the oil supplied from the brake pipe 11 will be as described above. Similarly, air flows into the conduit 9 through the through hole 14 of the first bolt 12, and when the inside of the conduit 9 is filled, air is then introduced into the through hole 15a of the first bolt 12 and the through hole 17 of the second bolt 16. Oil flows while being discharged, and eventually oil overflows to the outside. Thereafter, the second bolt 16 is tightened to complete air bleeding.

In this way, according to this embodiment, air can be easily bleed using the mounting bolt 12 of the brake pipe 11, so there is no need to form a dedicated port for air bleed as in the conventional example, which improves workability. As a result, costs can be reduced.

Furthermore, in this embodiment, when oil is introduced from the brake pipe 11 into the conduit 9, the oil inflow passage (through hole 14) and the air discharge passage (through hole 15) are separated (i.e., in series). Therefore, air can be removed effectively and in a short time.

As explained above, according to the present invention, the brake pipe mounting bolt is configured to also serve as an air breather seat, so the structure of the main body can be made compact and costs can be reduced.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the present invention, FIG. 2 is a sectional view of the main part thereof, and FIGS. 3 and 4 are sectional views showing the shape of the tip of the air bleeding bolt. DESCRIPTION OF SYMBOLS 11... Brake pipe, 11A... Brake pipe ring part, 12... First bolt, 14... Through hole for brake oil inflow, 15... Through hole for air discharge, 16... Second bolt.

Claims (1)

[Scope of utility model registration request] In a hydraulic brake device, an air discharge passage is formed by passing through the axis of a mounting bolt inserted into a brake pipe ring, and the air discharge passage is communicated with the brake pipe. A brake circuit air bleed device characterized in that a second bolt is screwed to open and close communication with the outside.