JP3928165B2 - Transmission with interlock mechanism - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a transmission in a vehicle such as a tractor, and more particularly to a gear-type transmission provided with an interlock mechanism.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, it is well known that a gear-type transmission is provided with an interlock mechanism to prevent double meshing of a transmission gear, and a shift fork shaft unexpectedly slides and shifts in a transmission equipped with the interlock mechanism. In general, a detent mechanism for imparting moderation (response) during operation is also provided.
[0003]
FIG. 9 is a cross-sectional view of an interlock mechanism and a detent mechanism portion in a conventional transmission as viewed from a direction perpendicular to the shift fork shaft. As shown in FIG. 9, in the conventional transmission, one end of the shift fork shaft is supported by the hanger member 100 that is separably attached to the casing, and the interlock mechanism is provided on the hanger member. Had the problems shown.
[0004]
That is, as shown in the drawing, the hanger member 100 is formed along the axial direction of each shift fork shaft in order to support one end of each of the first, second, and third shift fork shafts 101, 102, 103. The first, second, and third bearing holes 104, 105, and 106 are formed in a direction perpendicular to the axial direction of the shift fork shaft from the upper end surface of the hanger so that the bearing holes communicate with the upper end surface of the hanger. The two detent guide holes 107, 108, 109 and the two formed in the direction perpendicular to the axial direction of the shift fork shaft from the side surface of the hanger member so as to communicate with each two of the bearing holes. Interlock guide hole 110 (in FIG. 9, only one interlock guide hole is shown).
[0005]
Between the first and second shift fork shafts and between the second and third shift fork shafts in the interlock guide hole 110, spherical first shaft-second shaft interlock plungers 111 and second shafts, respectively. A third inter-axis interlock plunger 112 is provided, and a rod-shaped first-third inter-axis shaft is provided between the first to third shift fork shafts in the other interlock guide hole (not shown). An interlock plunger is provided, and an interlock mechanism is formed by each of these interlock plungers.
[0006]
Each detent guide hole 107, 108, 109 has a closing means 113 such as a bolt for closing the opening of the guide hole, and a detent plunger 114 inserted sequentially between the shift fork shaft and the closing means. And a biasing means 115 for pressing the detent plunger against the upper surface of the shift fork shaft, and a detent mechanism is formed by these members.
[0007]
When assembling the transmission configured as described above, first, the first shift fork shaft 101 is first inserted into the first bearing hole 104, and then the interlock guide hole 110 extending perpendicularly to the bearing hole is inserted into the first shift fork shaft 101. The second shift fork shaft 102 is inserted into the second bearing hole while the interlock plunger 111 between the first shaft and the second shaft is inserted and the plunger 111 is maintained at an intermediate position between the first bearing hole 104 and the second bearing hole 105. 105 need to be inserted. Further, after that, the second shaft-third shaft interlock plunger 112 is inserted from the interlock guide hole 110, and the plunger 112 is placed at an intermediate position between the second bearing hole 105 and the third bearing hole 106. And a first-third inter-axis interlock plunger is inserted from the other interlock guide hole (not shown), and the plunger is interposed between the first bearing hole 104 and the third bearing hole 106. It was necessary to insert the third shift fork shaft 103 into the third bearing hole 106 while maintaining the same. As described above, in the transmission according to the conventional configuration, it is necessary to perform the installation of the shift fork shaft and the arrangement of the interlock plunger in parallel, so it takes a lot of work to assemble the interlock mechanism, As a result, the assembly efficiency of the transmission itself has deteriorated, leading to a rise in product costs.
[0008]
Furthermore, since the hanger member 100 requires drilling in three directions, ie, a bearing hole, a detent guide hole, and an interlock guide hole, and the processing takes time, the hanger member was used. As a result, the cost of the transmission itself increased.
[0009]
[Problems to be solved by the invention]
The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a transmission with an interlock mechanism that can improve the assembly efficiency and reduce the cost.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a casing having front and rear and left and right side walls that are erected in a substantially vertical direction, and a bearing hole formed in two opposite side walls of the side walls. A plurality of shift fork shafts slidably supported in the axial direction; and an interlock plunger disposed between the two shift fork shafts. A gear-type transmission including an interlock mechanism that disables sliding, wherein the casing has an extending portion that extends outward from a position lower than the bearing hole on one side wall having the bearing hole. Each of the shift fork shafts has a projecting portion that extends further outward from the bearing hole and is positioned on the extending portion, and the interlock plunger includes a shift shaft Arranged between the fork shaft protrusions, the extension holds the interlock plunger such that it can move between each two shift fork shafts in a direction perpendicular to the axial direction of these shafts. It has a holding | maintenance part, and this holding | maintenance part provides the transmission with an interlock mechanism by which upper part was made into the opening which can insert the said interlock plunger.
[0011]
Preferably, the extending portion is formed with a receiving groove that accommodates the protruding portion of each shift fork shaft and has an upper opening, and the holding portion communicates with each of the two receiving grooves and has an upper portion. The communication groove may be an opening, and the casing may be detachably provided with a member for closing the upper opening of the housing groove and the communication groove.
[0012]
Furthermore, the present invention is slidable in the axial direction in substantially the same plane by a casing having front and rear and left and right side walls erected in a substantially vertical direction, and bearing holes formed in two opposing side walls of the side walls. And an interlock that disables simultaneous sliding of two or more shift fork shafts by means of an interlock plunger that acts on the shift fork shafts. The casing has an extending portion extending outwardly from a position below the bearing hole on one of the side walls having the bearing hole, and the three The shift fork shaft has a protruding portion that extends further outward from the bearing hole and is positioned on the extending portion, and the second shift fork shaft is orthogonal to the axial direction at the protruding portion. And the interlock plunger is disposed in the through hole of the second shift fork shaft and between the first and third shift fork shafts and the second shift fork shaft. The extension portion is disposed at a position corresponding to the through hole of the second shift fork shaft, and the extending portion is an interface disposed between the first and third shift fork shafts. It has a holding part which holds a lock plunger so that it can move in the direction perpendicular to the direction of an axis of these axes between two corresponding axes, and the above-mentioned holding part inserts the interlock plunger The present invention provides a transmission with an interlock mechanism that has a possible opening.
[0013]
Preferably, the extension portion is formed with first, second, and third receiving grooves that receive the protruding portions of the shift fork shaft and that are open on the upper side, respectively. An interlock plunger holding portion disposed between the fork shaft and the second shift fork shaft communicates with the first housing groove and the second housing groove, and the second housing groove and the third housing groove, respectively. As the communication groove having an upper opening, the casing may further include a member for closing the upper opening of the housing groove and the communication groove in a detachable manner.
[0014]
More preferably, the closing member may be provided with a detent mechanism.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
A preferred embodiment of a transmission with an interlock mechanism according to the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a longitudinal side view of a transmission according to the present embodiment, and FIGS. 2 and 3 are cross-sectional views taken along lines AA and BB in FIG. 1, respectively.
[0016]
As shown in FIGS. 1 to 3, a transmission 1 according to the present embodiment includes a casing 10, a cover 40 that is detachably attached to the casing, a gear-type transmission mechanism 3, and a clutch in the gear-type transmission mechanism. A shift fork 5 that engages with the slider 4; shift fork shafts 20, 21, and 22 that support the shift fork in a non-slidable manner in the axial direction; and a select arm 6 that slides the shift fork shaft along the axial direction. And a select shaft 7 for supporting the select arm.
[0017]
In the present embodiment, there are three gear-type transmission mechanisms each having a pair of transmission gear trains having different transmission ratios and performing two-stage transmission (in FIG. 1, of the three gear-type transmission mechanisms). 2), and three shift fork shafts 21, 22, and 23 are provided corresponding to each gear type transmission mechanism (see FIG. 2).
[0018]
The casing has front and rear wall surfaces 11, 12 and left and right side surfaces 13, 14 erected substantially vertically so as to face each other. In the present embodiment, the clutch housing rear wall forms the casing front wall 11.
[0019]
The front wall 11 and the rear wall 12 of the casing wall surfaces are first and first for supporting the front and rear ends of the first, second, and third shift fork shafts 21, 22, 23, respectively. 2, third bearing holes 11a, 11b, 11c and 12a, 12b, 12c are formed, and each shift fork shaft is supported by the bearing holes so as to be slidable in the axial direction. Further, the transmission casing rear wall 12 is formed with an extending portion 30 extending outward from a position below the bearing holes 12a, 12b, and 12c.
[0020]
The extending portion 30 is formed with receiving grooves 31, 32, 33 that communicate with bearing holes 12a, 12b, 12c formed in the rear wall 12, respectively. The receiving grooves 31, 32, 33 have protrusions 21a, 22a that protrude further outward from the bearing holes 12a, 12b, 12c of the first, second, and third shift fork shafts 21, 22, 23. , 23a are accommodated. In the present embodiment, the shift fork shafts 21, 22, and 23 are configured to be supported along the vehicle longitudinal direction by the front and rear walls 11 and 12, and the extending portion is formed on the casing rear wall. However, instead of this, it is also possible to support the shift fork shaft by the left and right side walls 13 and 14 and to form an extension corresponding to this on either side wall.
[0021]
FIG. 4 shows an enlarged perspective view of the accommodation groove before the shift fork shaft is supported. As shown in FIG. 4, each of the receiving grooves 31, 32, 33 is open at the top, and further, the second receiving groove 32 located in the middle in plan view is the first receiving groove 31 located on both sides. In addition, the distance is shorter than the third accommodation groove 33 by a predetermined distance. In addition, the side walls 34, 35, and 36 that define the respective housing grooves are formed with notches 34a, 35a, and 36a that connect the two housing grooves defined thereby. That is, the notches 34a, 35a, and 36a are provided between the first receiving groove 31 and the second receiving groove 32, between the second receiving groove 32 and the third receiving groove 33, and between the first receiving groove 31 and the third receiving groove, respectively. A communication groove communicating between 33 is formed.
[0022]
As shown in FIG. 2, the notches 34a, 35a, and 36a have first and second shift fork shafts, second and third shift fork shafts, and first and third shift fork shafts, respectively. Interlock plungers 37, 38 and 39 are provided. Each notch is formed to communicate with the receiving groove in a direction orthogonal to the axial direction of the shift fork shaft, and each interlock plunger is moved only along the direction orthogonal to the axial direction of the corresponding shift fork shaft. The holding means to obtain is comprised. In the present embodiment, the extending portion has an accommodation groove defined by a side wall, and the notch formed in the side wall is used as an interlock holding means. An extending portion having a horizontal lower end surface and having an interlock plunger holding means projecting from the lower end surface may be used.
[0023]
In order to form an interlock mechanism, as shown in FIG. 2, recesses 21 </ b> A and 21 </ b> B are formed on the inner side surface of the first shift fork shaft 21, and recesses 22 </ b> A and 22 </ b> B are formed on both side surfaces of the second shift fork shaft 22. On the inner side surface of the third shift fork shaft 23, recesses 23A and 23B are respectively formed. Each concave portion is formed at a position where the corresponding shift fork shaft can engage with the corresponding interlock plunger when the gear-type transmission mechanism is neutralized. That is, for example, when the first shift fork shaft 21 is slid from the neutral position to any one of the axial directions, the first and second shift fork shaft interlock plungers 37 move into the recesses 22A of the second shift fork shaft. And the first to third shift fork shaft interlock plunger 39 is pushed into the recess 23B of the first shift fork shaft, whereby the second and third shift fork shafts become non-slidable. In this way, an interlock mechanism that prevents simultaneous sliding of two or more shift fork shafts is formed.
[0024]
Further, as shown in FIGS. 1 and 4, a cover 40 that closes the upper opening of the housing groove and the notch is detachably attached to the casing 10 by appropriate fixing means such as a bolt. The cover is configured to include a detent mechanism. Hereinafter, the cover will be described in detail with reference to FIGS. 5 is an enlarged view of a portion C in FIG. 1, and FIGS. 6 and 7 are a sectional view taken along line DD and a sectional view taken along line EE in FIG. 5, respectively.
[0025]
As shown in FIGS. 5 to 7, the cover 40 is formed with through holes 41, 42, and 43 that communicate the receiving grooves with the upper end surface of the cover. On the other hand, three recesses 21C, 21D, 21E, 22C, 22D, 22E and 23C, 23D, 23E are formed along the axial direction on the upper surface of each shift fork shaft (see FIG. 1). . Of the three recesses, the recesses 21C, 22C, and 23C located in the middle are recesses for neutral positions, and the through holes 41, 42, and 43 are respectively provided when the gear-type transmission mechanism corresponding to each of the recesses is set to the neutral state. Are formed so as to face each other. And, when the gears in the corresponding gear-type transmission mechanism are connected to each other on both sides in the axial direction across the recesses 21C, 22C and 23C for the neutral position, respectively, at the positions facing the through holes, respectively. Recesses 21D, 21E, 22D, 22E, and 23D, 23E are formed.
[0026]
The upper end of each through hole is closed by a position adjusting member 44 that can be locked so as to be position adjustable along the axial direction of the through hole. As the position adjusting member, various members such as a bolt can be used. A spherical detent plunger 45 and a biasing member 46 that presses the detent plunger toward the upper surface of the shift fork shaft are inserted between the upper surfaces of the shift fork shafts 21, 22 and 23 and the lower end surface of the position adjusting member 44. Has been. In the present embodiment, by providing the cover 40 having such a detent mechanism, the interlock plungers 37, 38, 39 disposed in the notches 34a, 35a, 36a are prevented from falling off, and the neutral position is set. In addition, it is possible to prevent the shaft of the shift fork shafts 21, 22, and 23 from being shifted at each shift position. Further, the driver is given a moderate feeling of moderation (responsiveness) at the time of the shifting operation, thereby enabling an appropriate shift operation.
[0027]
According to the transmission configured as described above, when the shift fork shaft is assembled, after the first shift fork shaft is attached as in the prior art, the first and second shift fork shaft interlock plungers are moved to a predetermined position. There is no need to mount the shift fork shaft and the interlock plunger alternately, such as mounting the second shift fork shaft shaft and then mounting the shift fork shaft and the interlock plunger mounting operation independently. Can be done. That is, after each shift fork shaft 21, 22, 23 is attached to the casing 10 alone, all the interlock plungers 37, 38, 39 are disposed in the notches 34a, 35a, 36a from above, and thereafter Since the cover 40 may be attached, the assembly efficiency of the interlock mechanism portion in the transmission can be greatly improved.
[0028]
In addition, the detent mechanism in the present embodiment is configured so that it can be assembled after the cover 40 is fixed to the transmission casing 10, so that the assembly efficiency of the transmission is not deteriorated by providing the detent mechanism.
[0029]
Furthermore, as shown in FIG. 9, the hanger member used in the prior art required drilling in the three axial directions. In the present embodiment, the bearing hole is formed integrally with the casing body, and the blocking member is formed. Since the hole drilling is limited to only one direction, the cost can be reduced even in terms of the hole drilling cost.
[0030]
The gist of the present invention is to allow the mounting of the shift fork shaft and the disposition of the interlock plunger in separate processes, thereby improving the assembly efficiency of the transmission equipped with the interlock mechanism. Therefore, various configurations of the interlock mechanism can be applied. That is, in the present embodiment, an interlock mechanism having an interlock plunger is provided between each of the two shift fork shafts. Instead, for example, as shown in FIG. The second and third shift fork shafts 51, 52, 53 are arranged in the same plane, and the through hole 52A is located in the same plane and in a direction perpendicular to the axial direction of the second shift fork shaft 52. And a rod-like interlock plunger 58 is inserted into the through hole 52A, and a spherical interlock plunger 57 is inserted between the first and second shift fork shafts and between the second and third shift fork shafts. , 59 can be used. In the present embodiment, the shift fork shaft is provided with three shafts. However, the present invention is not limited to such a configuration, and is applied to a transmission having two or more shift fork shafts. You can also.
[0031]
【The invention's effect】
According to the transmission with the interlock according to the present invention, the extending portion extending outward is provided on the side wall of the casing, and the interlock plunger is perpendicular to the axial direction of these shafts between the shift fork shafts in the extending portion. Since the holding portion that is held so that it can move in any direction and the upper portion is an opening into which the interlock plunger can be inserted is formed, the assembly efficiency of the interlock mechanism portion can be greatly improved, Thereby, the cost reduction of transmission itself can be aimed at.
[0032]
In addition, an accommodating groove is formed in the extending portion, and one end portion of the shift fork shaft is accommodated in the accommodating groove, and the holding portion is configured by a notch formed in a side wall that defines the accommodating groove. Thus, the shift fork shaft can be slid more stably and the interlock plunger can be held more stably.
[0033]
Furthermore, if the member which closes the upper opening of the said accommodation groove | channel and the holding | maintenance part is provided with respect to the said casing so that attachment or detachment is possible, drop-off | omission of the said interlock plunger can be prevented effectively.
[0034]
If the detent mechanism is provided on the closing member, the detent mechanism can be provided without deteriorating the assembly efficiency.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a transmission according to a preferred embodiment of the present invention.
FIG. 2 is a cross-sectional view taken along the line AA in FIG.
FIG. 3 is a cross-sectional view taken along the line BB in FIG.
4 is a partial assembly perspective view of a portion C in FIG. 1. FIG.
FIG. 5 is an enlarged view of a portion C in FIG. 1;
FIG. 6 is a cross-sectional view taken along the line DD in FIG.
FIG. 7 is a cross-sectional view taken along line EE in FIG.
FIG. 8 is a partial plan sectional view showing a transmission according to another embodiment of the present invention.
FIG. 9 is a cross-sectional view of an interlock mechanism and a detent mechanism portion in a transmission according to the prior art.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Transmission 10 Casing 21,22,23 Shift fork shaft 30 Extension part 37,38,39,57,58,59 Interlock plunger 40 Cover

Claims (5)

A plurality of shifts supported in a substantially parallel and axially slidable manner by a casing having front and rear and left and right side walls erected in a substantially vertical direction and bearing holes formed in two opposite side walls of the side walls. A fork shaft, and an interlock mechanism that has an interlock plunger disposed between the two shafts of the shift fork shaft, and prevents the simultaneous sliding of two or more shift fork shafts by the interlock plunger. Geared transmission,
The casing has, on one of the side walls having a bearing hole, an extending portion extending outward from a position lower than the bearing hole,
Each of the shift fork shafts has a protruding portion that extends further outward from the bearing hole and is positioned on the extending portion,
The interlock plunger is disposed between the protrusions of the shift fork shaft,
The extending portion has a holding portion that holds the interlock plunger so that the interlock plunger can be moved between each two shift fork shafts in a direction perpendicular to the axial direction of these shafts.
A transmission with an interlock mechanism, wherein the holding portion has an upper opening through which the interlock plunger can be inserted. The extension portion is formed with an accommodation groove that accommodates the protruding portion of each shift fork shaft and has an upper opening.
The holding portion is a communication groove that communicates with each of the two accommodation grooves and has an upper opening.
The transmission with an interlock mechanism according to claim 1, wherein a member for closing an upper opening of the housing groove and the communication groove is detachably provided in the casing. A casing having front and rear and left and right side walls erected in a substantially vertical direction, and bearing holes formed in two opposite side walls of the side walls, are slidable in an axial direction in a substantially same plane, and are substantially parallel in order. A gear including a supported first, second, and third shift fork shafts and an interlock mechanism that disables simultaneous sliding of two or more shift fork shafts by an interlock plunger acting on the shift fork shafts. Type transmission,
The casing has, on one of the side walls having a bearing hole, an extending portion extending outward from a position lower than the bearing hole,
The three shift fork shafts have projections that extend further outward from the bearing holes and are positioned on the extending portions, and the second shift fork shafts have a direction perpendicular to the axial direction at the projections. Has through-holes facing,
The interlock plunger is formed in the through hole of the second shift fork shaft and between the first and third shift fork shafts and the second shift fork shaft, Arranged in the corresponding position,
The extending portion allows an interlock plunger disposed between the first and third shift fork shafts and the second shift fork shaft to be perpendicular to the axial direction of these shafts between the two corresponding shafts. It has a holding part that holds it so that it can move in the direction,
A transmission with an interlock mechanism, wherein the holding portion has an upper opening through which the interlock plunger can be inserted. The extension portion is formed with first, second, and third receiving grooves that each receive the protruding portion of the shift fork shaft and have an upper opening.
The interlock plunger holder disposed between the first and third shift fork shafts and the second shift fork shaft includes the first housing groove, the second housing groove, the second housing groove, and the second housing groove. Each of the three receiving grooves communicates with each other and has an upper opening.
The transmission with an interlock mechanism according to claim 3, wherein a member for closing an upper opening of the housing groove and the communication groove is detachably provided in the casing. The transmission with an interlock mechanism according to claim 2 or 4, wherein the closing member is provided with a detent mechanism.

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