JP4223445B2 - Air breather and air breather breather pipe mounting method - Google Patents

Description

  The present invention relates to an air breather and a breather pipe mounting method for an air breather in an automobile transmission.

  In general, in case bodies such as transmission cases into which lubricating oil is injected, it is necessary to ventilate to suppress changes in the air pressure inside the case due to the expansion and contraction of air inside the case. An air breather is provided for communicating the inside and outside of the case body through a vent.

  The air breather structure of the transmission generally has a structure in which the inside and outside of the transmission case are connected by a breather pipe, but an air breather structure of a clutch chamber opening type in which the inside of the transmission case and the inside of the clutch case are connected by a breather pipe is also proposed.

  This air releaser structure of the clutch chamber opening type has an advantage that the number of parts can be reduced because the breather pipe is not opened to the outside air, so that it is not necessary to attach a cap or a plug to the tip of the breather pipe.

  A conventional air breather structure of a clutch chamber opening type will be described with reference to FIGS. FIG. 1 is an end view of a conventional clutch case at a portion defining a breather chamber, and FIG. 2 is a sectional view taken along line AA in FIG.

  In the conventional air breather of the clutch chamber opening type, the breather chamber 10 is defined by the partition wall 6 of the clutch case 2 and the partition wall 8 of the transmission case 4 as shown in FIG. The breather pipe 12 is press-fitted into the clutch case 2, and the breather chamber 10 is opened in the clutch case 2.

  A breather plate 13 is screwed to the clutch case 2. The breather plate 13 is a kind of baffle plate for preventing wear pieces or the like due to the engagement / disengagement of the clutch in the clutch case 2 from entering the breather pipe 12 and entering the transmission.

Although many structures have been proposed for the air breather, most of them are of the type that opens directly to the outside air from the transmission case, and examples of the prior art include the following.
JP-A-8-219259 Japanese Patent Laid-Open No. 11-303975 JP 2000-356260 A Utility Model Registration No. 2605308 Japanese Utility Model Publication No. 7-10652 Japanese Utility Model Publication No. 7-17204

  As shown in FIG. 2, in a conventional clutch chamber opening type air breather, a linear breather pipe 12 is press-fitted into the clutch case 2. In such a breather structure, the following problems occur when it is difficult to secure a sufficient breather chamber capacity due to layout reasons.

  The oil swept up by the gear, particularly the final driven gear, enters the breather chamber 10 as shown by an arrow 15 in FIGS. 1 and 2 and becomes a mist. Depending on the conditions, the mist-like oil may become an inner wall of the breather pipe 12. Adhere to. When the symptom progresses, there is a problem that a minute amount of oil comes out in the clutch chamber as a result. That is, there is a problem that “breather blowing” or “oil blowing” occurs.

  In order to prevent this breather blow, various structures have been proposed in the above-mentioned patent documents, but there are problems such as a complicated breather structure, and there is no simple method for attaching a breather pipe in the prior art. Not mentioned.

  The present invention has been made in view of these points, and an object of the present invention is to provide an air breather and a simple breather pipe mounting method capable of significantly suppressing breather blowing in a clutch chamber open type air breather. It is to be.

According to the first aspect of the present invention, in the method for attaching a breather pipe of an air breather of the clutch chamber opening type in which the inside of the transmission case and the inside of the clutch case are communicated with each other by a breather pipe, the case abutting protrusion and the pipe guide having a predetermined depth are provided at one end Prepare a jig having a hole, insert a linear breather pipe into the pipe guide hole of the jig, and attach the tip of the breather pipe to the pipe press-fitting hole formed in the clutch case. The impact is applied to the other end, and the breather pipe is driven into the pipe press-fitting hole until the case abutting protrusion comes into contact with the clutch case wall. Pushing downward and bending the transmission case side of the breather pipe downward by a predetermined angle Breather Mounting pipes Aburiza is provided.

According to a second aspect of the present invention, in the breather pipe attaching method according to the first aspect , the step of bending the transmission case side of the breather pipe downward by a predetermined angle is formed at the end of the partition wall of the clutch case that defines the breather chamber. There is provided a breather pipe mounting method achieved by pushing the other end side of the jig downward with the case abutting protrusion as a fulcrum until the side of the jig hits.

According to the first aspect of the present invention, there is provided a breather pipe mounting method for an air breather capable of press-fitting a linear breather pipe into a pipe press-fitting hole and further easily bending the breather chamber side by a predetermined angle.

According to the second aspect of the present invention, the breather pipe can be bent at a predetermined angle only by abutting the side surface of the jig against the end of the partition wall of the clutch case that defines the breather chamber. Man-hours can be reduced.

  Referring to FIG. 3, there is shown a longitudinal sectional view of a 5-speed manual transmission to which the present invention is applied. In the clutch case 2 and the transmission case 4, a main shaft 14, a counter shaft 16 and a reverse shaft 18 are arranged in parallel to each other.

  Reference numeral 20 denotes a clutch. The clutch 20 is connected to a crankshaft 22 of an engine (not shown) and selectively transmits engine power to the main shaft 14.

  Between the input shaft 14 and the counter shaft 16, there are provided a plurality of transmission gear trains that define the respective shift stages from the first speed to the fifth speed. That is, the first speed gear train 24, the second speed gear train 26, the third speed gear train 28, the fourth speed gear train 30, and the fifth speed gear train 32 are arranged in this order from the right side in the axial direction.

  The first speed gear train 24 includes a drive gear 36 that is integrated with the main shaft 14 and a driven gear 38 that is rotatably attached to the counter shaft 16. The drive gear 36 and the driven gear 38 mesh with each other.

  The second gear train 26 includes a drive gear 40 that is integrated with the main shaft 14 and a driven gear 42 that is rotatably attached to the counter shaft 16. The drive gear 40 and the driven gear 42 mesh with each other.

  The third-speed gear train 28 includes a drive gear 44 that is rotatably attached to the main shaft 14 and a driven gear 46 that is fixedly attached to the counter shaft 16. The drive gear 44 and the driven gear 46 mesh with each other. .

  The fourth-speed gear train 30 includes a drive gear 48 that is rotatably attached to the main shaft 14 and a driven gear 50 that is fixedly attached to the counter shaft 16. The drive gear 48 and the driven gear 50 mesh with each other. .

  The fifth speed gear train 32 includes a drive gear 52 that is rotatably attached to the main shaft 14 and a driven gear 54 that is fixedly attached to the counter shaft 16. The drive gear 52 and the driven gear 54 mesh with each other. .

  Switching between the transmission gear trains is performed by three synchro mechanisms 60, 62, and 64. The first synchronization mechanism 60 is provided on the counter shaft 16 between the first speed driven gear 38 and the second speed driven gear 42.

  The second synchronization mechanism 62 is provided on the main shaft 14 between the third speed drive gear 44 and the fourth speed drive gear 48. The third synchronization mechanism 64 is provided on the main shaft 14 adjacent to the fifth speed drive gear 52.

  Except at the time of a shift change, the power of the main shaft 14 is transmitted to the countershaft 16 via the transmission gear train selected by the operation of the synchro mechanisms 60, 62, 64.

  Then, after being decelerated by the final reduction gear ratio of the final reduction gear train composed of the final drive gear 66 and the final driven gear 68, it is transmitted to the differential device 70. As a result, the drive wheel rotates in the forward direction.

  On the other hand, at the time of reverse, first, all the synchronization mechanisms 60 to 64 are set to the neutral state. The first reverse gear 72 that is rotatably attached to the reverse shaft 18 always meshes with the first-speed drive gear 36, and the second reverse gear 76 that is rotatably attached to the reverse shaft 18 is fixed to the counter shaft 16. It always meshes with the attached reverse driven gear 74.

  In this state, when a reverse shift fork (not shown) is operated, the second reverse gear 76 is coupled to the first reverse gear 72. Thereby, the power of the main shaft 14 is transmitted to the countershaft 16 via the first speed drive gear 36, the first reverse gear 72, the second reverse gear 76, and the reverse driven gear 74.

  At the time of reverse, the power is transmitted to the countershaft 16 via the first and second reverse gears 72 and 76. Therefore, the rotation direction of the countershaft 16 is opposite to that at the time of forward movement, and the drive wheels are moved in the reverse direction. Rotate.

  Referring to FIG. 4, there is shown an end view of the clutch case at a portion defining the breather chamber in the manual transmission shown in FIG. 3. 5 is a cross-sectional view taken along line AA in FIG. In the description of the embodiment of the present invention, the same components as those of the conventional structure shown in FIGS. 1 and 2 are denoted by the same reference numerals.

  As best shown in FIG. 5, a breather chamber 10 is defined by the partition wall 6 of the clutch case 2 and the partition wall 8 of the transmission case 4 in the vicinity of the contact portion between the clutch case 2 and the transmission case 4.

  A breather type 80 having a breather chamber side bent downward is press-fitted into the clutch case 2, and the breather chamber 10 is communicated (opened) into the clutch case 2. In the present embodiment, since the breather pipe 80 is bent downward by a predetermined angle on the breather chamber 10 side, the oil adhering to the inner wall of the breather pipe 80 can be forcibly returned to the transmission case 4, which is a conventional problem. It is possible to effectively prevent so-called breather blowing or oil blowing, in which a small amount of oil oozes out into the clutch chamber.

  The air breather of the present invention is not limited to the structure shown in FIG. 5, and the following modifications can be considered. In the first modification, the breather pipe on the clutch chamber side may be bent upward. In the second modification, the inner diameter of the breather pipe on the clutch chamber side may be reduced. Furthermore, as a third modification, a straight breather pipe may be obliquely press-fitted so that the breather chamber side is lowered.

  Next, the breather pipe mounting method of the present invention will be described with reference to FIGS.

  In the breather pipe mounting method of the present invention, a jig 82 as shown in FIG. 6 is used. The jig 82 has a case abutting portion 82a and a pipe guide hole 83 having a predetermined depth on one end side. This predetermined depth is determined by the driving depth (pressing depth) of the breather pipe into the clutch case.

  First, as shown in FIG. 7, a linear breather pipe 84 is inserted into the pipe guide hole 83 of the jig 82, and the distal end of the breather pipe 84 is applied to the pipe press-fitting hole 2 a formed in the clutch case 2. An impact is applied to the other end of the tool 82 with a hammer or the like.

  The breather pipe 84 is driven into the pipe press-fitting hole 2a until the tip of the case abutting protrusion 82a of the jig 82 comes into contact with the clutch case wall.

  Next, as shown in FIG. 8, the other end side (right side) of the jig 82 is the end of the partition wall 6 of the clutch case 2, with the case abutting protrusion 82 a of the jig 82 as a fulcrum. Press down until it contacts 6a.

  By this simple operation using the jig 82, the breather pipe 84 can be driven and the pipe can be bent at a predetermined angle in a continuous process. As a result, the pipe bending cost and assembly man-hour can be reduced.

It is an end view of the clutch case of the part which defines the conventional breather chamber. It is the sectional view on the AA line of FIG. 1 is a longitudinal sectional view of a manual transmission to which the present invention is applicable. It is an end view of the clutch case of the part which defines the air breather of this invention embodiment. It is the sectional view on the AA line of FIG. It is a perspective view of the jig | tool used for the breather pipe attachment method of this invention. It is a figure explaining the attachment method of the breather pipe of the present invention. It is a figure explaining the attachment method of the breather pipe of the present invention.

Explanation of symbols

2 Clutch case 4 Transmission case 6, 8 Partition wall 10 Breather chamber 13 Breather plate 80, 84 Breather pipe 82 Jig 82a Case abutting projection 83 Pipe guide hole

Claims (2)

In the breather pipe mounting method for the air breather of the clutch chamber opening type in which the inside of the transmission case and the inside of the clutch case are communicated by the breather pipe.
Prepare a jig that has a case abutting protrusion and a pipe guide hole of a predetermined depth on one end side,
Insert a straight breather pipe into the pipe guide hole of the jig,
While applying the tip of the breather pipe to the pipe press-fitting hole formed in the clutch case, impact is applied to the other end of the jig, and the breather pipe is moved until the case abutting protrusion comes into contact with the clutch case wall. Drive into the pipe press-fitting hole,
Using the case abutting protrusion as a fulcrum, push the other end of the jig downward to bend the transmission case side of the breather pipe downward by a predetermined angle,
A breather pipe mounting method for an air breather. The step of bending the transmission case side of the breather pipe downward by a predetermined angle includes supporting the case abutting portion until the side surface of the jig contacts the end of the partition wall on the clutch case side defining the breather chamber. Air breather breather pipe mounting method according to claim 1, wherein the achieved by pressing the other end of the jig downward as.

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