JPH0477810B2 - - Google Patents

Description

Detailed Description of the Invention (Industrial Application Field) The present invention is used for the purpose of quickly bringing various hydraulically operated friction elements (clutches, etc.) of automatic transmissions into a non-operating state when hydraulic pressure disappears. This invention relates to an air bleed device.

(Prior Art) This type of air bleed device is normally used to drain hydraulic fluid from clutches and brakes, which serve as friction elements, quickly when switching from operation to non-operation. Recently, in order to improve the above-mentioned hydraulic oil drainage characteristics, instead of or in addition to installing an air bleed device on the piston, an air bleed device is installed on a housing other than the piston to drain the hydraulic oil. "SHOP MANUAL for 1982 IMPALA and 4 other cars" published by GM AUTOMATIC
Listed in TRANSMISSION 700R4.

(Problem to be solved by the invention) However, this air bleed device
Since the air bleed device is inserted as shown in the figure a and has a hole in the same direction as the output axis b, the axial dimension of the parts (clutch housing, brake housing) in which the air bleed device is installed becomes long, especially at the front. This is a disadvantage when an automatic transmission is placed in a narrow engine room, such as in a front-engine vehicle.

SUMMARY OF THE INVENTION An object of the present invention is to provide an air bleed device for an automatic transmission that can shorten the automatic transmission in the axial direction while not restricting the air intake speed.

(Means for Solving the Problems) For this purpose, the present invention converges the air bleed passage at its end open to the atmosphere, and when the ball leaves the position in contact with this convergence part, air is sucked into the air bleed passage. In the air bleed device for an automatic transmission as described above, a separate member is inserted and fixed into the atmosphere-opening end of the air bleed passage, and at the tip of the separate member in the insertion direction, starting from the surface of the tip, The convergent portion is arranged such that the diameter becomes smaller as the distance from the convergent portion increases, and the separate member is arranged such that the opening direction of the convergent portion is oriented in a radial direction about the input and output shafts of the automatic transmission. It is characterized by being oriented to

(Example) Hereinafter, the present invention will be explained in detail with reference to illustrated examples.

1 to 4 show an embodiment of the air bleed device of the present invention. In this example, this air bleed device is provided on a pump cover 1 for a high clutch H/C as shown in FIG. The high clutch is also a well-known air bleed device A for the piston P.
shall have the following.

FIG. 4 shows an automatic transaxle (automatic transmission with differential gear) of a front engine front wheel drive vehicle, and engine power is input to this transaxle via a torque converter T/C. In addition to the above high clutch H/C, band brake B/B,
It is equipped with friction elements of a reverse clutch R/C, a low clutch L/C, and a low reverse brake LR/B, and the engine power from the torque converter T/C is shifted at a gear ratio determined by the selective hydraulic operation of these elements, and the shifting power is Gear set G1, output shaft O/S,
It is transmitted to the left and right drive wheels sequentially through gear set G2 and differential gear D/G.

Then, the hydraulic oil for selective hydraulic operation (speed change control) of the friction elements is supplied to the oil pump O/
This oil pump, which is powered by the oil discharged from P, is driven by the engine via a torque converter T/C. Therefore, the oil pump is housed in a pump housing formed in a converter housing C/H that surrounds the torque converter T/C, and covered by a pump cover 1.

The air bleed device for the high clutch H/C in this embodiment is provided to the pump cover 1 as follows. That is, as shown in FIGS. 1 to 3, an air bleed passage 2 is bored in the pump cover 1, and one end of the air bleed passage 2 is connected to the hydraulic oil passage T of the high clutch H/C.
(see FIG. 4), and the other end is opened to the outer circumferential surface 1a of the pump cover 1 to serve as an end open to the atmosphere. As shown in FIG. 3, the air bleed passage 2 extending in the radial direction of the pump cover 1 has an open end portion 2 close to the outer peripheral surface of the pump cover.
The stepped portion 3 is set such that a has a large diameter, and the remaining portion 2b has a larger diameter than the passage 2 but has a smaller diameter than the portion 2a.

A sleeve-shaped separate member 4 is press-fitted into the portion 2a until it collides with the stepped portion 3, and the separate member is oriented toward the transmission center axis, and the ball 5 is housed in the portion 2b. The inner periphery of one end of the separate member 4 close to the ball 5 is set as a converging portion 4a as a conical tapered surface that converges as it moves away from the ball 5, and the large diameter end of the converging portion has a larger diameter than the ball 5, but has a smaller diameter. The end has a smaller diameter than the ball 5 and is continuous with the other end cylindrical surface 4b of the separate member 4.

Air bleed passage part 2b on pump cover 1
A pin 6 is driven across the convergent part 4a, thereby restricting the movement of the ball 5 in the direction away from the converging part 4a. The driving position of the pin 6 is determined so as to produce the following.

The operation of the above embodiment will be explained next.

When the high clutch H/C is operated, its operating pressure also reaches the air bleed passage 2, pressing the ball 5 against the converging portion 4a. In this way, the high clutch operating pressure is not removed from the center hole of the separate member 4, and the air bleed device of this embodiment, which is composed of the air bleed passage 2, the separate member 4, the ball 5, and the pin 6, prevents the high clutch from operating. It has no effect on the When the high clutch is deactivated due to loss of high clutch operating pressure, the ball 5 separates from the converging portion 4a and falls onto the pin 6 due to gravity. Thus,
Air is sucked into the air bleed passage 2 to quickly dissipate the high clutch operating pressure, and the air bleed device of this embodiment can quickly deactivate the high clutch.

(Effects of the Invention) Thus, in the air bleed device of the present invention, for example, with the above-described configuration, a separate member 4 is inserted and fixed into the atmosphere-opening end 2a of the air bleed passage 2, and at the tip of the separate member 4 in the insertion direction, Starting from the tip surface,
The convergent portion 4a is formed by arranging the converging portion 4a so that the diameter becomes smaller as it goes away from this surface, and the opening of the convergent portion 4a is fixed so as to face in the radial direction with the input/output shaft of the automatic transmission as the central axis. The member that forms the air bleed passage (the pump cover 1 in the illustrated example) can be made shorter in the axial direction of the automatic transmission than in the conventional example in which the air bleed passage has an end open to the atmosphere oriented in the axial direction.

Further, according to the air bleed device of the present invention, due to the above configuration, the separate member 4 does not have a cylindrical portion continuous to the converging portion 4a to accommodate the ball 5, and the following effects can also be achieved.

That is, the cylindrical part needs to have a strength capable of resisting the radial binding force when it is fixed (press-fitted) into the atmosphere-opening end 2a of the air bleed passage 2, and needs to be thicker than a certain level. This thick wall can be achieved by increasing the outer diameter or reducing the inner diameter of the cylindrical part, but the former measure requires increasing the diameter of the air-opening end 2a of the air bleed passage 2. The effect of the present invention, which is that the axial dimension of the automatic transmission can be shortened, is canceled out, and the latter measure also cancels out the effect of shortening the axial dimension of the automatic transmission.
The gap between the two becomes smaller, and the speed at which air is sucked through the gap is limited, making it impossible to fully demonstrate the original air bleed function.

By the way, in the air bleed device of the present invention, since the separate member 4 does not have a cylindrical part connected to the converging part 4a and housing the ball 5, the above-mentioned concerns are eliminated and the axial dimension of the automatic transmission can be shortened. While maintaining the aforementioned effects of the present invention, the original air bleed function can be fully exerted.

[Brief explanation of the drawing]

FIG. 1 is a front view showing a pump cover of an automatic transmission equipped with an air bleed device according to an embodiment of the present invention, FIG. 2 is a side view thereof, and FIG. 3 is a cross-sectional view taken from FIG. Figure 4 shows figures 1 to 3.
FIG. 5 is a developed sectional view of an automatic transmission equipped with an example air bleed device, and FIG. 5 is a sectional view showing a conventional air bleed device. DESCRIPTION OF SYMBOLS 1...Pump cover, 2...Air bleed passage, 3...Shoulder part, 4...Separate member, 4a...Convergent part, 5...Ball, 6...Ball support pin.

Claims (1)

[Claims] 1. An air bleed device for an automatic transmission in which the air bleed passage converges at its end open to the atmosphere, and when the ball leaves the position in contact with the converged portion, air is sucked into the air bleed passage. In this step, a separate member is inserted and fixed in the atmosphere-opening end of the air bleed passage, and a diameter of the separate member starts from the surface of the tip and becomes smaller as the distance from this surface increases. The automatic transmission is characterized in that the separate member is oriented such that the opening of the converging portion is oriented in a radial direction with the input and output shafts of the automatic transmission as a central axis. Air bleed device for transmission.