Transmission and method for manufacturing a transmission

Abstract

The present invention provides a transmission and a method for manufacturing a transmission that can reduce driver discomfort. [Solution] In the transmission TM according to the present invention, the outer peripheral edge of the boss portion 20 of the plate member 2 is cut out by a notch 23 for more than half its circumference. As a result, the rigidity near the boss portion 20 is reduced, and the frequency of the collision sound generated when the first stopper member 81 and the second stopper member 82 collide with the boss portion 20 during shift operation can be reduced. This reduces driver discomfort.

Description

Technical Field

[0001] The present invention relates to a transmission device that switches gear positions by swinging a shift lever, and a method for manufacturing the transmission device.

Background Art

[0002] As a conventional transmission device that switches gear positions by swinging a shift lever, for example, the one described in Patent Document 1 below is known.

[0003] Briefly explained, in the conventional transmission device, a metal protrusion provided at the lower part of the shift lever is brought into contact with a pair of metal stoppers, a first stopper and a second stopper, which are provided in pairs at the front and rear ends of the stroke of the shift lever, respectively, whereby the displacement amount of the shift lever is regulated.

[0004] Also, at this time, in the conventional transmission device, a bush for imparting a sense of moderation in the swinging of the shift lever was provided in such a manner as to be interposed between the protrusion and the stopper. That is, the front end wall provided at the front end of the bush was interposed between the first stopper and the protrusion, and the rear end wall provided at the rear end of the bush was interposed between the second stopper and the protrusion. As a result, a configuration was adopted in which the protrusion did not directly collide with the stopper.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, with the structure of the conventional transmission described above, in the case of a transmission that does not have the bushing, the protrusion will directly collide with the stopper, and there is a risk that noise and vibration will be generated by this collision. In particular, since this collision between metal members generates noise and vibration at a relatively high frequency, there is still room for improvement as it can cause discomfort to the driver.

[0007] Therefore, the present invention was devised in view of the technical problems related to the conventional transmissions, and aims to provide a transmission and a method for manufacturing a transmission that can reduce driver discomfort. [Means for solving the problem]

[0008] A transmission according to the present invention, in one embodiment, includes a transmission case including a first casing and a second casing divided in the axial direction; a plate member interposed between the first casing and the second casing so as to partition the space between the first casing and the second casing, and sandwiched between the first casing and the second casing; a striking rod housed inside the transmission case, inserted through a rod insertion hole provided in the plate member, and moving axially in conjunction with a shift lever; and a component provided on one axial side of the striking rod, which abuts against the plate member and controls the striking rod. The device comprises: a first stopper member that restricts movement in the other axial direction; a second stopper member provided on the other axial side of the striking rod and in contact with the plate member to restrict movement in one axial direction of the striking rod; a first stopper contact portion provided on one axial end face of a cylindrical boss portion provided on the outer peripheral edge of the rod insertion hole in the plate member, and to which the first stopper member can contact; a second stopper contact portion provided on the other axial end face of the boss portion, and to which the second stopper member can contact; and a notch cut out continuously in the circumferential direction over more than half a circumference of the outer peripheral edge of the boss portion, which penetrates the plate member in the axial direction.

[0009] Furthermore, in one embodiment, a method for manufacturing a transmission according to the present invention includes a transmission case including a first casing and a second casing divided in the axial direction; a plate member interposed between the first casing and the second casing so as to partition the space between the first casing and the second casing, and sandwiched between the first casing and the second casing; a striking rod housed inside the transmission case, inserted through a rod insertion hole provided in the plate member, and moving axially in conjunction with a shift lever; a first stopper member provided on one axial side of the striking rod and in contact with the plate member to restrict the movement of the striking rod on the other axial side; a second stopper member provided on the other axial side of the striking rod and in contact with the plate member to restrict the movement of the striking rod on the one axial side; and a cylindrical boss provided on the outer peripheral edge of the rod insertion hole in the plate member. The plate member comprises a first stopper contact portion provided on one axial end face of the boss portion, to which the first stopper member can abut; a second stopper contact portion provided on the other axial end face of the boss portion, to which the second stopper member can abut; and a notch portion cut out continuously in the circumferential direction for more than half a circumference of the outer peripheral edge of the boss portion, which penetrates the plate member in the axial direction, wherein the notch portion comprises a first notch portion provided on one circumferential end side, a second notch portion provided on the other circumferential end side, and the first notch portion and the second notch portion are connected A method for manufacturing a transmission including a continuous intermediate notch, comprising: a first step of forming the plate member by casting, and forming the first and second notches, which are separated from each other via a connecting portion that connects a flange portion and the boss portion provided on the outer edge of the plate member during the casting process, by casting out; and a second step of forming the intermediate notch by connecting the first and second notches by cutting off the connecting portion by machining. [Effects of the Invention]

[0010] According to the present invention, the outer peripheral edge of the boss portion of the plate member is cut out by a notch that extends more than half its circumference. As a result, the rigidity near the boss portion is reduced, making it possible to reduce the frequency of the collision sound generated when the first stopper member and the second stopper member collide with the boss portion during shift operation. This reduces driver discomfort. [Brief explanation of the drawing]

[0011] [Figure 1] This is a schematic diagram showing the external structure of the transmission according to the present invention. [Figure 2] This is a schematic diagram showing the internal structure of the transmission according to the present invention, where (a) is the state when shifted to 3rd gear and (b) is the state when shifted to 4th gear. [Figure 3] Figure 1 is an enlarged view of the main part of the plate member shown. [Figure 4] This is an enlarged view of the main part of a plate member illustrating a method for manufacturing a transmission according to the present invention, where (a) is the first step and (b) is the second step. [Modes for carrying out the invention]

[0012] Below, an embodiment of the transmission and manufacturing method of the transmission according to the present invention will be described in detail with reference to the drawings. In the following embodiment, an example will be given in which the transmission according to the present invention is applied to a manual transmission for an automobile.

[0013] (Transmission configuration) Figure 1 shows a schematic diagram illustrating the external structure of the transmission TM according to this embodiment.

[0014] As shown in Figure 1, the transmission TM according to this embodiment has a shift element (not shown) that constitutes the shift mechanism housed inside the transmission case 1. The transmission case 1 is divided in the longitudinal direction of the vehicle and has a first casing 11 located on the front side of the vehicle and a second casing 12 located on the rear side of the vehicle. The first casing 11 and the second casing 12 are fastened together by bolts and nuts (not shown).

[0015] Furthermore, in the middle section of the transmission case 1, a plate-shaped plate member 2 is interposed between the first casing 11 and the second casing 12, separating the first casing 11 and the second casing 12. The plate member 2 is sandwiched between the first casing 11 and the second casing 12 and is fixed in place by fastening together with bolts and nuts (not shown) that fasten the first casing 11 and the second casing 12.

[0016] Figure 2 is a schematic diagram showing the internal structure (shift mechanism) of the transmission TM according to this embodiment, where (a) shows the state when shifted to 3rd gear and (b) shows the state when shifted to 4th gear. Note that in Figure 2, the transmission case 1 is omitted for the sake of explaining the internal structure. Also, in the explanation of Figure 2, the left side of Figure 2, which corresponds to the front of the vehicle, is defined as "front," and the right side of Figure 2, which corresponds to the rear of the vehicle, is defined as "rear."

[0017] As shown in Figure 2, the transmission TM has a striking rod 4 connected to a shift lever 3 inside a transmission case 1 (see Figure 1) (not shown), which passes through a rod insertion hole 200 provided in a plate member 2 and is inserted across a first casing 11 (see Figure 1) and a second casing 12 (see Figure 1) (not shown).

[0018] The striking rod 4 is supported by bearing portions provided in a first casing 11 (see FIG. 1) and a second casing 12 (see FIG. 1), which are not shown, so as to be rotatable in the circumferential direction and movable forward and backward in the axial direction. A striking guide 40 is fixed to the rear end portion of the striking rod 4, and the other end portion of the shift lever 3 with one end facing the driver's seat is engaged with a recess 400 provided in the striking guide 40.

[0019] Further, a striking lever 5 is attached to the striking rod 4, and a plurality of fork rods 62 each having a shift fork 61 attached thereto are selectively linked to the striking lever 5. The striking lever 5 has a cylindrical tubular base portion 51 that fits over the striking rod 4 and an engagement projection portion 52 provided so as to project outward in the radial direction of the tubular base portion 51. By the engagement projection portion 52 being engaged with an engagement groove 64 of a bracket 63 provided on each fork rod 62, the striking lever 5 is selectively linked to each fork rod 62.

[0020] Then, as shown in FIGS. 2(a) and 2(b), the transmission TM strokes the striking rod 4 in the axial direction by rocking the shift lever 3 back and forth, and thereby the striking lever 5 integrally moves in the axial direction, and the selected fork rod 62 moves the shift fork 61 in the axial direction. As a result, the shift fork 61 moves the coupling sleeve 7 in the axial direction, and the synchronizing member 8 meshes with the transmission gear train 9, thereby shifting to a predetermined gear stage.

[0021] Incidentally, the transmission gear train 9 illustrated in FIG. 2 is, for example, a gear train with 3 - 4 speeds, and has a 3 - speed main gear MG3 and a 4 - speed main gear MG4. Specifically, as shown in FIG. 2(a) for example, by swinging the shift lever 3 forward to move the striking rod 4 forward and moving the fork rod 62 and the shift fork 61 forward, the synchro gear SG meshes with the 3 - speed main gear MG3 via the coupling sleeve 7, and the gear is shifted to the 3 - speed stage. Similarly, as shown in FIG. 2(b) for example, by swinging the shift lever 3 backward to move the striking rod 4 backward and moving the fork rod 62 and the shift fork 61 backward, the synchro gear SG meshes with the 4 - speed main gear MG4 via the coupling sleeve 7, and the gear is shifted to the 4 - speed stage.

[0022] Further, the striking rod 4 is provided with a pair of stopper members 8, namely a first stopper member 81 and a second stopper member 82, which regulate the displacement amount of the striking rod 4 during the shift operation. By the first stopper member 81 and the second stopper member 82, which are the pair of stopper members 8, respectively contacting the axial end surface of the plate member 2, the axial displacement amount of the striking rod 4 is regulated.

[0023] Specifically, the striking lever 5 has a cylindrical base 51 configured as the first stopper member 81. That is, during the 3 - speed shift operation, as shown in FIG. 2(a), the rear end portion 810 of the cylindrical base 51, which is the first stopper member 81, contacts the axial one - end surface of the plate member 2, thereby making it possible to regulate the backward movement of the striking rod 4 to an appropriate stroke amount.

[0024] Furthermore, the striking rod 4 is provided with a cylindrical second stopper member 82 on the opposite side in the axial direction from the first stopper member 81, with the plate member 2 in between. That is, during the 4th gear shift operation, as shown in Figure 2(b), the front end 820 of the second stopper member 82 abuts against the other axial end face of the plate member 2, thereby restricting the forward movement of the striking rod 4 to an appropriate stroke amount.

[0025] (Plate component configuration) Figure 3 shows an enlarged view of the main part of the plate member 2, which is an enlarged view of the area near the upper end of the plate member 2 shown in Figure 1.

[0026] As shown in Figure 3, the plate member 2 has a relatively thick flange portion 21 that is continuously provided in the circumferential direction on its outer edge, and this flange portion 21 is sandwiched between the first casing 11 and the second casing 12. Multiple bolt insertion holes 22, namely the first bolt insertion holes 221 and the second bolt insertion holes 222, which are inserted through the flange portion 21 along the axial direction, through which bolts (not shown) that fasten the first casing 11 and the second casing 12 are inserted.

[0027] Furthermore, near the bolt insertion hole 22 at the upper end of the plate member 2, a boss portion 20 is provided through which a rod insertion hole 200, through which a striking rod 4 is inserted, is generally located in the center. The rod insertion hole 200 is a generally circular through hole that penetrates along the axial direction, and is located on the inner circumference side of the first bolt insertion hole 221 and the second bolt insertion hole 222, at a position where the center Qx of the rod insertion hole 200 is approximately equidistant from the centers Q1 and Q2 of the first bolt insertion hole 221 and the second bolt insertion hole 222, respectively. In other words, the first bolt insertion hole 221 and the second bolt insertion hole 222 are positioned so that their respective centers Q1 and Q2 are approximately equidistant from the center Qx of the rod insertion hole 200.

[0028] Furthermore, a generally annular first stopper contact portion 201, capable of contacting the first stopper member 81, is continuously provided circumferentially on one axial end face of the boss portion 20 of the plate member 2. The first stopper contact portion 201 is composed of a flat surface perpendicular to the direction of movement (stroke) of the first stopper member 81. Similarly, a generally annular second stopper contact portion 202, capable of contacting the second stopper member 82, is continuously provided circumferentially on the other axial end face of the boss portion 20 of the plate member 2. The second stopper contact portion 202 is composed of a flat surface perpendicular to the direction of movement (stroke) of the second stopper member 82.

[0029] Furthermore, the plate member 2 is provided with a notch 23 in the outer peripheral region of the boss portion 20, which is formed by continuously cutting out the outer peripheral region of the boss portion 20 in the circumferential direction for approximately half a circumference or more. This notch 23 extends in the circumferential direction to a position that coincides with a first imaginary line L1, which connects the center Q1 of the first bolt insertion hole 221 and the center Qx of the rod insertion hole 200. Similarly, the notch 23 extends in the circumferential direction to a position that coincides with a second imaginary line L2, which connects the center Q2 of the second bolt insertion hole 222 and the center Qx of the rod insertion hole 200.

[0030] Here, the notch portion 23 has a first notch portion 231 and a second notch portion 232 formed by casting during the casting of the plate member 2, and an intermediate notch portion 233 formed by machining after casting of the plate member 2, which connects the first notch portion 231 and the second notch portion 232. Overall, the outer circumference of the first stopper contact portion 201 and the second stopper contact portion 202 is notched out by more than half a circumference in the circumferential direction. The first notch portion 231 extends to the region on one side of the circumferential direction of the rod insertion hole 200 and is notched out to a position that overlaps with at least the first imaginary line L1. On the other hand, the second notch portion 232 extends to the region on the other side of the circumferential direction of the rod insertion hole 200 and is notched out to a position that overlaps with at least the second imaginary line L2.

[0031] (Manufacturing method for transmissions) Figure 4 is an enlarged view of the main part of the plate member 2 showing the method for forming the notch 23 of the plate member 2 in the manufacturing method of the transmission TM according to this embodiment, where (a) shows the first step and (b) shows the second step.

[0032] In manufacturing the notches 23 of the plate member 2, first, as shown in Figure 4(a), the plate member 2 is formed by casting, and at the same time, the first notches 231 and the second notches 232 are formed by casting (first step). At this point, the first notches 231 and the second notches 232 are separated by a connecting portion 24 that connects the boss portion 20 and the flange portion 21, and are in a state of mutual independence and non-communication. In this embodiment, the provision of the connecting portion 24 ensures that molten metal flows to the boss portion 20 during the casting of the plate member 2.

[0033] Next, after the first step, as shown in Figure 4(b), the connecting portion 24 is cut away by machining (cutting) to form an intermediate notch 233 that connects the circumferential ends of the first notch 231 and the second notch 232 which are opposite each other in the circumferential direction (second step). As a result, a series of notches 23 are formed in the outer peripheral regions of the first stopper contact portion 201 and the second stopper contact portion 202 of the plate member 2.

[0034] (Effects of this embodiment) As described above, in the transmission TM according to this embodiment, the outer peripheral edge of the boss portion 20 of the plate member 2 is cut out by the notch portion 23 for more than half its circumference. As a result, the rigidity near the boss portion 20 is reduced, and it is possible to reduce the frequency of the collision sound generated when the first stopper member 81 and the second stopper member 82 collide with the boss portion 20 during shift operation. This reduces driver discomfort.

[0035] Furthermore, as in this embodiment, the rigidity of the plate member 2 is increased near the first bolt insertion hole 221 and the second bolt insertion hole 222, through which a bolt (not shown) is inserted and fixed in a clamped state between the first casing 11 and the second casing 12. As a result, when the first stopper member 81 and the second stopper member 82 collide, a relatively high-frequency collision sound is generated, which the driver may find unpleasant.

[0036] In contrast, in the transmission TM according to this embodiment, the notch 23 is provided near the flange portion 21 through which a plurality of bolt insertion holes (for example, the first bolt insertion hole 221 and the second bolt insertion hole 222 in this embodiment), which are fastening parts of the plate member 2, pass. This makes it possible to effectively reduce the rigidity near the boss portion 20, and thus effectively reduce driver discomfort.

[0037] Furthermore, as in this embodiment, if a notch 23 extending more than half the circumference of the outer edge of the boss portion 20 is formed solely by casting, the molten metal may not easily flow (spread) to the boss portion 20, potentially leading to casting defects in the plate member 2.

[0038] In contrast, in the manufacturing method of the transmission TM according to this embodiment, in the first step, the first notch 231 and the second notch 232, which are isolated by the connecting portion 24, are formed by casting, and then in the second step, the connecting portion 24 is removed by machining (cutting) to form the intermediate notch 233. In this way, when forming the notch 23, the notch 23 is formed in two steps: the first step of forming the first notch 231 and the second notch 232 by casting, and the second step of forming the intermediate notch 233 by machining. This suppresses casting defects in the boss portion 20, and reduces the rigidity near the boss portion 20 by the notch 23, thereby reducing the frequency of the collision sound between the first stopper member 81 and the second stopper member 82.

[0039] The present invention is not limited to the configurations illustrated in the above embodiments, and can be freely modified according to, for example, the specifications of the transmission TM to which the present invention is applied. [Explanation of Symbols]

[0040] 1…Transmission case 11…First casing 12…Second casing 2…Plate component 20... Boss section 200…Rod insertion hole 201...First stopper contact section 202...Second stopper contact section 21…Flange section 221...First bolt insertion hole (bolt insertion hole) 222...Second bolt insertion hole (bolt insertion hole) 23... Notch 231...First notch 232...Second notch 233...Intermediate notch 24...Connection part 4…Striking Rod 81...First stopper member 82...Second stopper member L1…First virtual line L2…Second virtual line TM... Transmission

Claims

1. A transmission case including a first casing and a second casing divided in the axial direction, A plate member is interposed between the first casing and the second casing so as to separate them, and is sandwiched between the first casing and the second casing, A striking rod is housed inside the transmission case, inserted through a rod insertion hole provided in the plate member, and moves axially in conjunction with the shift lever. A first stopper member is provided on one axial side of the striking rod and contacts the plate member to restrict the movement of the striking rod on the other axial side, A second stopper member is provided on the other axial side of the striking rod and contacts the plate member to restrict the movement of the striking rod in the axial direction on one side. The plate member has a first stopper contact portion provided on one axial end face of a cylindrical boss portion provided on the outer peripheral edge of the rod insertion hole, which the first stopper member can contact, A second stopper contact portion is provided on the other axial end face of the boss portion, and the second stopper member can contact a second stopper contact portion, The outer edge of the boss portion is continuously cut out in the circumferential direction for more than half its circumference, and the notch penetrates the plate member in the axial direction, A transmission equipped with a gearbox.

2. A transmission according to claim 1, The outer edge of the plate member is provided with multiple bolt insertion holes through which multiple bolts are inserted. The plate member is fastened together with the first casing and the second casing via the bolts inserted through the bolt insertion holes. The boss portion is positioned close to the bolt insertion hole, The notch is provided in the circumferential region interposed between the boss portion and the bolt insertion hole in the radial direction of the boss portion. Transmission.

3. A transmission according to claim 2, The plurality of bolt insertion holes include a first bolt insertion hole and a second bolt insertion hole. The notches are provided in the circumferential region that overlaps with a first imaginary line connecting the center of the rod insertion hole and the center of the first bolt insertion hole, and a second imaginary line connecting the center of the rod insertion hole and the center of the second bolt insertion hole, thereby separating the first bolt insertion hole and the second bolt insertion hole from the boss portion. Transmission.

4. A transmission case including a first casing and a second casing divided in the axial direction, A plate member is interposed between the first casing and the second casing so as to separate them, and is sandwiched between the first casing and the second casing, A striking rod is housed inside the transmission case, inserted through a rod insertion hole provided in the plate member, and moves axially in conjunction with the shift lever. A first stopper member is provided on one axial side of the striking rod and contacts the plate member to restrict the movement of the striking rod on the other axial side, A second stopper member is provided on the other axial side of the striking rod and contacts the plate member to restrict the movement of the striking rod in the axial direction on one side. The plate member has a first stopper contact portion provided on one axial end face of a cylindrical boss portion provided on the outer peripheral edge of the rod insertion hole, which the first stopper member can contact, A second stopper contact portion is provided on the other axial end face of the boss portion, and the second stopper member can contact a second stopper contact portion, The outer edge of the boss portion is continuously cut out in the circumferential direction for more than half its circumference, and the notch penetrates the plate member in the axial direction, Equipped with, The method for manufacturing a transmission includes a notch, which comprises a first notch provided on one end in the circumferential direction, a second notch provided on the other end in the circumferential direction, and an intermediate notch connecting the first notch and the second notch. A first step is to form the plate member by casting, and to form the first notch and the second notch, which are separated from each other by a connecting portion that connects the flange portion and the boss portion provided on the outer edge of the plate member during the casting process, by casting, A second step involves cutting off the connecting portion by machining to connect the first notch and the second notch and form the intermediate notch, A method for manufacturing a transmission having a transmission.

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