JP7479756B2 - transmission - Google Patents

Description

The present invention relates to a transmission.

Conventionally, in transmissions such as CVTs (Continuously Variable Transmissions), a valve body for controlling the supply of oil to each part is placed at the bottom of the case that forms the outer shell, and an oil pan that receives the oil is fixed to the case from the underside of the valve body with bolts. A strainer for filtering the oil drawn up from the oil pan is placed between the valve body and the oil pan.

Taking into account the behavior of the oil when the vehicle equipped with the transmission turns, starts, and stops, i.e., the change in the oil level stored in the oil pan, oil must be sucked up from the center of the oil pan into the strainer. For this reason, the strainer is positioned below the valve body, and the suction port that sucks oil into the strainer is formed in a position facing the center of the oil pan.

JP 2017-180711 A

If the oil pan is deformed due to an external impact, for example, there is a risk that the deformed oil pan may block the suction port of the strainer. For this reason, an oil pan guard has traditionally been provided to protect the oil pan and prevent deformation of the oil pan due to collisions with objects such as debris falling on the road.

However, since oil pan guards are made of metal and need to be thick enough to ensure strength against external impacts, they are heavy and costly, so the inventors of the present application wondered if it might be possible to eliminate the oil pan guard.
An object of the present invention is to provide a transmission that can suppress the occurrence of problems due to deformation of the oil pan even if the oil pan guard is eliminated.

To achieve the above object, the transmission of the present invention includes a case forming an outer shell, an oil pan attached to the case from below and receiving oil, a strainer provided above the bottom surface of the oil pan, which draws the oil received in the oil pan through a suction port and filters the oil thus drawn, and a valve body provided above the bottom surface of the oil pan and to which the oil filtered by the strainer is supplied, with the suction port being located above the lower end of the valve body.

According to this configuration, the strainer and valve body are provided above the bottom surface of the oil pan. The strainer's suction port is located above the lower end of the valve body. Therefore, even if the oil pan is deformed by an external impact, the deformation can be stopped by the lower end of the valve body. As a result, the strainer's suction port can be prevented from being blocked by a deformed oil pan.

Therefore, even if the oil pan guard is eliminated, the occurrence of the problem of the strainer's suction port becoming blocked can be suppressed. Furthermore, by eliminating the oil pan guard, it is possible to reduce the weight and cost of the vehicle.

It is preferable that an object to be protected from deformation of the oil pan is set, and a protrusion is provided that protrudes downwardly from the corresponding object to be protected, corresponding to the object to be protected including the suction port, and that the protrusion forms the lower end of the valve body.
With this configuration, the object to be protected can be effectively protected from deformation of the oil pan due to an external impact.

According to the present invention, even if the oil pan guard is eliminated, problems caused by deformation of the oil pan can be suppressed.

FIG. 4 is a bottom view of the inside of the unit case of the transmission unit. 2 is a cross-sectional view of the speed change unit taken along the line AA in FIG. 1 . 2 is a cross-sectional view of the speed change unit taken along the line BB shown in FIG. 1.

The following describes in detail an embodiment of the present invention with reference to the attached drawings.

Figure 1 is a view of the inside of the unit case 2 of the gear change unit 1 as seen from below. Figure 2 is a cross-sectional view of the gear change unit 1 taken along the line A-A in Figure 1. Figure 3 is a cross-sectional view of the gear change unit 1 taken along the line B-B in Figure 1.

The transmission unit 1 is a unit that is mounted on a vehicle and changes the speed of power generated by an engine as a drive source for traveling. The transmission unit 1 includes, for example, a torque converter and a belt-type CVT (Continuously Variable Transmission) within a unit case 2 that forms an outer shell.
In the following description, the directions of front, rear, left and right are based on the state in which the transmission unit 1 is mounted on a vehicle.

A valve body 3 is provided at the bottom of the unit case 2. The valve body 3 forms a hydraulic circuit including various valves for controlling the supply of oil to each part of the transmission unit 1. The various valves include a first solenoid valve 11, a second solenoid valve 12, a third solenoid valve 13, a fourth solenoid valve 14, and a fifth solenoid valve 15. The first solenoid valve 11, the second solenoid valve 12, and the third solenoid valve 13 are arranged side by side in this order from the right side in the left-right direction at the right front end of the unit case 2 when viewed from below inside the unit case 2. The fourth solenoid valve 14 is arranged at the left front end of the unit case 2 when viewed from below inside the unit case 2. The fifth solenoid valve 15 is arranged between the third solenoid valve 13 and the fourth solenoid valve 15.

A strainer 4 is provided at the bottom of the unit case 2. The strainer 4 includes a filtering section 21 that contains a filtering material, and a pipe section 22 that extends to the left from the filtering section 21. The pipe section 22 is formed in a hollow tube shape, and its interior is connected to the interior of the filtering section 21. The underside of the tip of the pipe section 22 is opened as a suction port 23 for sucking in oil.

As shown in FIG. 2, the oil pan 5 is fixed to the unit case 2 from below with multiple bolts. In FIG. 2, the bottom surface of the oil pan 5 is inclined downward to the right, but when the transmission unit 1 is mounted on the vehicle, the bottom surface of the oil pan 5 extends approximately parallel to the road surface.

The oil pump (not shown) generates suction force, which draws oil accumulated in the oil pan 5 into the pipe section 22 through the suction port 23. The oil drawn into the pipe section 22 flows through the pipe section 22 toward the filter section 21 and passes through the filter material provided in the filter section 21. As the oil passes through the filter material, foreign matter contained in the oil is captured by the filter material and removed from the oil. The oil that has passed through the filter material is supplied to the valve body 3. The oil is then supplied from the valve body 3 as hydraulic oil or lubricating oil to each part that requires a supply of oil, such as the torque converter and the continuously variable transmission.

As shown in FIG. 1, the first solenoid valve 11, the second solenoid valve 12, and the third solenoid valve 13 each include a valve section 16 having a port through which oil passes, and a coil section 17 that houses a coil and a plunger for changing the opening degree of the port. The valve section 16 is disposed in the valve body 3, and the coil section 17 protrudes forward from the valve body 3. The valve body 3 is provided with a thin plate-shaped rib 31 that extends between each of the valve sections 16 and the coil section 17 of the first solenoid valve 11, the second solenoid valve 12, and the third solenoid valve 13. As shown in FIG. 3, the lower end of the rib 31 protrudes downward beyond the first solenoid valve 11, the second solenoid valve 12, and the third solenoid valve 13.

As a result, the first solenoid valve 11, the second solenoid valve 12, and the third solenoid valve 13 are positioned above the lower end of the rib 31 that forms the lower end of the valve body 3. Therefore, even if the oil pan 5 is deformed by an external impact near the first solenoid valve 11, the second solenoid valve 12, or the third solenoid valve 13, the deformation can be stopped by the lower end of the rib 31. As a result, damage to the first solenoid valve 11, the second solenoid valve 12, and the third solenoid valve 13 by the deformed oil pan 5 can be suppressed.

A notch 32 is formed in a position offset to the left of the center of the rib 31 in the left-right direction, in other words, in a position between the second solenoid valve 12 and the third solenoid valve 13 in the left-right direction. Harnesses 33 for the first solenoid valve 11, the second solenoid valve 12, and the third solenoid valve 13 are passed through this notch 32, so that the rib 31 also serves as a guide for guiding the routing of the harnesses 33.

A cylindrical boss 34 for positioning and fixing the fourth solenoid valve 14 is provided to the left of the fourth solenoid valve 14 and protrudes downward from the valve body 3. The lower end of the boss 34 protrudes downward beyond the fourth solenoid valve 14.

As a result, the fourth solenoid valve 14 is positioned above the lower end of the boss 34, which forms the lower end of the valve body 3. Therefore, even if the oil pan 5 is deformed by an external impact near the fourth solenoid valve 14, the deformation can be stopped by the lower end of the boss 34. As a result, damage to the fourth solenoid valve 14 by the deformed oil pan 5 can be suppressed.

To the right of the fifth solenoid valve 15, a bolt fixing boss 36 is provided that protrudes downward from the valve body 3 and into which a bolt 35 for fixing the fifth solenoid valve 15 is screwed. The lower end of the bolt fixing boss 36 protrudes downward beyond the fifth solenoid valve 15.

As a result, the fifth solenoid valve 15 is positioned above the lower end of the bolt fixing boss 36 that forms the lower end of the valve body 3. Therefore, even if the oil pan 5 is deformed by an external impact near the fifth solenoid valve 15, the deformation can be stopped by the lower end of the bolt fixing boss 36. As a result, damage to the fifth solenoid valve 15 by the deformed oil pan 5 can be suppressed.

In addition, behind the fifth solenoid valve and to the left of the suction port 23 of the strainer 4, an oil vibration prevention rib 37 is formed as a bulge that bulges downward from the underside of the valve body 3 to partition a space for preventing oil vibrations of the line pressure regulated by the valve body 3. The lower end of the oil vibration prevention rib 37 is located below the suction port 23, as shown in FIG. 2.

As a result, the suction port 23 of the strainer 4 is positioned above the lower end of the oil vibration prevention rib 37 that forms the lower end of the valve body 3. Therefore, even if the oil pan 5 is deformed by an external impact near the suction port 23, the deformation can be stopped by the lower end of the oil vibration prevention rib 37. As a result, the suction port 23 of the strainer 4 can be prevented from being blocked by the deformed oil pan 5.

This effectively protects the first solenoid valve 11, the second solenoid valve 12, the third solenoid valve 13, the fourth solenoid valve 14, the fifth solenoid valve 15, and the suction port 23 of the strainer 4, which need to be protected from deformation of the oil pan 5 due to external impact. Therefore, even if the oil pan guard is eliminated, the occurrence of problems due to deformation of the oil pan 5 can be suppressed. Eliminating the oil pan guard can reduce the weight and cost of the vehicle.

Although one embodiment of the present invention has been described above, the present invention can be implemented in other forms, and various design modifications can be made to the above-described configuration within the scope of the matters described in the claims.

1: Gear unit (transmission)
2: Unit case (case)
3: Valve body 4: Strainer 5: Oil pan 11: First solenoid valve (object to be protected)
12: Second solenoid valve (protected object)
13: Third solenoid valve (protected object)
14: Fourth solenoid valve (protected object)
15: 5th solenoid valve (protected object)
23: Intake port (object to be protected)
31: Rib (protrusion)
34: Boss (protrusion)
36: Bolt fixing boss (protrusion)
37: Rib (protrusion) to prevent oil vibration

Claims (1)

A case forming an outer shell;
an oil pan attached to the case from below and receiving oil;
a strainer provided above a bottom surface of the oil pan, for drawing in the oil received in the oil pan through a suction port and filtering the drawn oil;
a valve body provided above the bottom surface of the oil pan and supplied with the oil filtered by the strainer,
The oil pan has three or more objects to be protected from deformation, including the suction port.
A transmission in which at least one protrusion is provided that corresponds to only one of the protected objects and protrudes downwardly relative to the one protected object, and one protrusion is provided that corresponds to at least two or more protected objects other than the one protected object and protrudes downwardly relative to the two or more protected objects, and all of the protected objects are positioned above the corresponding protrusions.

Images