JPS59194150A - Gear shifting device - Google Patents

Abstract

PURPOSE:To make a device very compact by slidably fitting a shift fork in a shift fork supporting shfat which is rotated by a shifting input and, further, combining a shift drum, which has a cam groove engaging with said shift fork, in an integrated form with said supporting shaft and concentrically arranging said shift fork supporting shaft and said shift drum. CONSTITUTION:The boss part 38a of a shift fork 38 is slidably fitted in a shift fork supporting shaft 37 and the fork part 38b of the shift fork 38 is engaged with the annular groove 36 provided on the outer periphery of the boss part 33a of a shift gear 33 in such a way that it interposes the boss part 33a. A shift drum 39 is combined in an integrated form with the shift fork supporting shaft 37 and a cam groove 88 is provided on its body part 39c, and the distance between the centers of the both groove ends 88a, 88b is set to be equal to the travelling distance of the shift gear 33. On the other hand, an engaging projection 87 which is engaged with the cam groove 88 is provided in an integrated form with the outer face of the boss part 38a of the shift fork 38.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a gear switching device using a shift drum.

Conventionally, this type of switching device has a shift drum rotated by switching input and a shift fork support shaft parallel to the shift drum supported in a transmission case and slidably fitted to the fork support shaft. A shift fork in which an engagement protrusion engages with a cam groove on a shift drum is widely used. Therefore, in such a structure, since the shift drum and the shift fork support shaft must be arranged radially apart from each other, there is a limit to how compact the shift drum can be made.

Therefore, an object of the present invention is to provide a compact device that enables concentric arrangement of a shift drum and a shift fork support shaft, and is characterized in that a shift fork support shaft rotated by a switching input is supported in a casing. death,
The shift fork support shaft is slidably fitted with a boss portion of a shift fork for shifting the switching gear, and further has a cam groove that engages with an engaging protrusion protruding from the outer surface of the boss portion. It consists of a shift drum that has been combined into one piece.

An embodiment of the present invention will be described below with reference to the drawings.

First, in FIGS. 1 to 3, the illustrated vehicle has a pair of left and right driving wheels Wf, Wf' and a power unit P for driving them at the front of a body frame F, and a driven wheel Wγ at the rear thereof. are arranged respectively.

The vehicle body frame F has support plates 1 a and 1 a for each front wheel.
A pair of left and right vertical members 1, 1' made upright, a plurality of horizontal members 2, 3, 4.5 that connect them in a ladder shape, and two horizontal members 3, 4 in the middle. A pair of reinforcing members 6 to be connected,
6' and the front parts of these so as to connect the longitudinal members 1, 1',
It is composed of three inverted U-shaped roll pars 7, 8, and 9 connected to the center and rear parts, and is surrounded by the front roll par 7, the frontmost cross member 2, and the left and right support plates 1a + 1a'. The central roll par 8 and the rear roll par 9 are connected at their tops via a reinforcing member 11. A steering column supporting a steering handle 13 is attached to the center of the front roll par 7.

Said pair of reinforcing members 6 along the center line between both longitudinal members 1, 1'
, 6', and this fuel tank 12 is bolted to the cross member 3 and both sleeve reinforcements -6, 6'.

A floor plate 16 is attached to the lower surface of the vehicle body frame F, and a front seat 14 for the driver and a passenger A are attached to the upper surface of the floor plate 16.
A rear seat 15 for the purpose is installed, and at that time, these backrests 14α and 15α are approximately ? i=? It is arranged like 5. Of course, the heights of these rollpers 8 and 9 are selected in advance so that they pass over the heads of the driver and passenger A, respectively.

In Figures 4 to 6, the power unit P consists of an engine E and a pair of left and right belt type automatic transmissions M, M' disposed on both sides of the rear of the engine.
M' is equipped with a reduction gear mechanism R on the output side.

The engine E is arranged with its crankshaft 20 facing in the left-right direction of the vehicle, and has an output shaft 21 on one side of the crankshaft 20, and a primary inertia force balancing shaft 2 on the other side.
2. A pump drive shaft 23 and a starting motor 24 are each arranged parallel to the crankshaft 20. A generator 25 is attached to one end of the crankshaft 20, and a centrifugal automatic starting clutch 26 is attached to the other end, and a forward/reverse switching device 27 is provided between the clutch 26 and the output shaft 21. .

This device 27 includes a drive gear 28 fixed to the output member of the clutch 26, a relay gear 29 rotatably supported by the output shaft 21 and always in mesh with the drive gear 28, and a crankshaft 20.
A small-diameter first idle gear 3 is rotatably supported on an idle shaft 30 parallel to the same, and is also in constant mesh with the drive gear 28.
1. A large-diameter second idle gear 32 integrally connected to the first idle gear 31, and a relay gear 29 and a second idle gear 32.
It is comprised of a switching gear 33 that is slidably spline-fitted to the output shaft 21 adjacent to the idle gear 32. The switching gear 33 is movable along the output shaft 21 between a forward position on the right and a reverse position on the left in FIG. 5A, via a central neutral position. gear 29
This switching gear 33 and relay gear 29
is provided with a drag clutch consisting of a dog 34 and a dog hole 35 that can engage with each other, and in the reverse position, the dog clutch 34, 35 is released so that the switching gear 33 meshes with the second idle gear 32. It has become.

Therefore, if the switching gear 33 is placed in the forward position, the crankshaft 200 rotation torque is transferred to the starting clutch 26, the drive gear 28,
The signal is transmitted to the output shaft 21 through the relay gear 29 and the switching gear 33 in order, and is rotated in the normal direction to move the vehicle forward. Furthermore, if the switching gear 33 is shifted to the reverse position, the rotational torque is transferred to the starting clutch 26, the driving gear 28, and the first
The signal is transmitted to the output shaft 21 through the idle gear 31, the second idle gear 32, and the switching gear 33 in order, and is reversed.
The vehicle can be moved backwards.

In order to provide the switching gear 33 with the above-mentioned switching, the gear switching device of the present invention is provided as follows (see FIGS. 5A to 5C).

A shift fork support shaft 37 parallel to the output shaft 21 is rotatably supported by a pair of left and right bearings 70a and 70b provided in the casing 7o of the power unit P. An operating lever 40 is fixed to the left end of the shift fork support shaft 37 that protrudes outside the casing 70, and switching input from a gear shift lever (not shown) is applied to the shift fork support shaft 37 via the operating lever 4o. .

A boss portion 38a of a shift fork 38 is slidably fitted into the shift fork support shaft 37, and the shift fork 38
The fork portion 38b is connected to the boss portion 33 of the switching gear 33.
b It is engaged with the annular groove 36 provided on the outer periphery so as to sandwich the boss portion 334 therebetween. The outer periphery of the shift fork support shaft 37 is provided with three annular locking grooves 17f, 17n, and 17τ corresponding to the forward, neutral, and reverse positions of the switching gear 33, while the boss portion of the shift fork 38 3B, a locking method 18 that can selectively engage the locking grooves 17f, 17n, and 17r, and a locking method 18 that can be selectively engaged with the locking grooves 17f, 17+z.
, 17r is provided.

In addition, a shift drum 39 is attached to the shift fork support shaft 37.
are integrally combined. The shift drum 39 is made of a press, and has a pair of left and right end walls 39a and 39b that are supported through the shift fork support shaft 37 at a position adjacent to the bearing 7 (lz170A), and both end walls 39a and 39b are connected.
It also includes a body portion 39c that is concentric with the shift fork support shaft 37 and surrounds approximately half the circumference of the boss portion 38h of the shift fork 38. Right end wall portion 39h of this shift drum 39
The fitting part of the shift fork support shaft 3γ and the shift fork support shaft 3γ have an occluded cross section, and both 3γ and 39 can rotate together, but the axial direction is Movement is prevented.

9- Body 39 of shift drum 39. is provided with a cam groove 88, which includes an inclined groove 8B inclined with respect to the generatrix of the circumferential surface of the body portion 39c, and a pair of rows extending from both ends of the inclined groove 88c in a direction perpendicular to the generatrix. Stop groove 88
(L? 88h, double-sided blind groove 88α,
The center-to-center distance of 88h should be set equal to the distance between the forward and reverse positions of the switching gear 33. On the other hand, an engagement protrusion 8γ that engages with the cam groove 88 is integrally formed on the outer surface of the boss portion 38α of the shift fork 38.

Therefore, when the switching gear 33 is placed in the neutral position, the locking method 18 of the shift fork 38 is in the central locking groove 1.
The engagement protrusion 87 is engaged with the y-ru to prevent the shift fork 38 from moving inadvertently, and the engagement protrusion 87 occupies the center position of the inclined groove 88c. Therefore, if the operating lever 40 is operated to rotate the shift drum 39 in one direction or the other, the guiding action of the inclined groove 88c will cause the shift fork 33 to move to the right or left via the engaging protrusion 8T. and shift the switching gear 33 to the forward or reverse position. When the switching gear 33 reaches such a position, the locking method 18 changes the engagement position to the right or left engagement grooves 1γf, 17r to prevent the shift fork 38 from moving inadvertently. On the other hand, the engagement protrusion 8γ enters the dead end groove 88a or 88b, but in such a state, the dead end groove 88a or 88h restrains the left and right movement of the engagement protrusion 81, so the shift fork 3B Even if it receives thrust from the gear 33, it will not be displaced left or right, that is, the given switching position can be secured.

The -order inertia force balancing shaft 22 is connected to drive gears 41 having the same diameter.
and is synchronously rotated from the crankshaft 20 via the driven gear 42. This balance shaft 220 weight 22α is connected to the crankshaft 2
It is provided at a position where IF enters between the pair of opposing crank webs 20a and 20α when the weight 22α approaches 0, but the primary inertial force balancing effect of the engine E by this weight 22α is well known, so the explanation thereof is as follows. Omitted.

The pump drive shaft 23 is driven by the crankshaft 20 via a chain transmission 43. A lubricating pump 44 is connected to one end of the pump drive shaft 23, and a cooling water pump is connected to the other end, and the water pump 45 can be easily attached and detached as follows.

That is, the rotating shaft 4γ having the water pump 1450 impeller 46 is connected to the pump drive shaft 23 via a removable joint 48, and the pump housing 49 supporting the rotating shaft 4T and accommodating the impeller 46 is connected to the engine. It is fixed to the crankcase 50 of E with bolts 51. Therefore, by removing the bolts 51, the water pump 45 can be easily taken out from the engine E, which is convenient for maintenance.

Incidentally, when the engine E is an air-cooled type, the water pump 45 is removed in this way, and an appropriate blind cover is provided on the opening of the crankcase 50 behind the pump housing 49.

As shown in FIGS. 5A and 57), the generator 25
The signal protrusion 5 of the ignition pulser is on the outer peripheral surface of the rotor 25α.
The pick-up coil 53 of the ignition pulser is bolted to a fixed support base 54 in the crankcase 50 so that its base plate 53α faces the turning path of the signal protrusion 52 with a certain gap. 55. In order to facilitate position adjustment and attachment/detachment of this pick-up coil 53, a working window 56 is provided in the end wall of the crankcase 50 facing the pink-up coil 53, and this window 56 is normally closed by a cap 5γ. Ru.

13- The pair of belt type automatic transmissions M and M' are connected to both ends of the output shaft 210 of the engine E and the left and right drive wheels Wf.

rv f/. Therefore, both driving wheels Wf and Wf' are each driven by an automatic transmission M.
, M' are connected to the output shaft 21 in parallel.

Since the belt type automatic transmissions M and M' have the same structure, only the structure of the one on the left M will be explained.

A variable diameter drive pulley 58 is attached to the end of the output shaft 21, and a variable diameter driven pulley 59 is attached to the driven shaft 61, which is the input shaft of the reduction gear mechanism R.
, 59, an endless belt 60 is stretched between them. The driving pulley 58 includes a centrifugal mechanism 62 that operates to increase its effective diameter as its rotational speed increases, while the driven pulley 59 includes a spring 63 that constantly operates to increase its effective diameter. , these centrifugal mechanisms 62 and springs 63
Due to this interaction, the gear ratio 14- between the output shaft 21 and the driven shaft 61 is automatically decreased as the rotational speed of the output shaft 210 increases.

A wheel drive shaft 65 is provided at the outer end of the output shaft 64 of the reduction gear mechanism R.
is spline-coupled, and further to this wheel drive shaft 65,
An axle 67 fixed to the no-pro 6 of the drive wheel Wf is connected via a constant velocity joint 68. Therefore, the power that has been shifted and transmitted to the driven shaft 61 is appropriately torque amplified by the reduction gear mechanism R, and then transmitted to the axle 61 via the wheel drive shaft 65 and the constant velocity joint 68 to drive the drive wheel Wf. do. ' Since the left and right drive wheels Wf, Wf' are connected in parallel to the output shaft 21 via such automatic transmissions M, rW', both seat drive wheels Wf are connected due to turning of the vehicle, etc.

If a rotational speed difference occurs in Wfl, a difference will occur in the gear ratios of both automatic transmissions M and M', and as a result, the output torque of the output shaft 21 will be equal to the rotational speed of both driving wheels Wf and Wf'. distributed among them accordingly. That is, automatic transmission M
, M' each perform a normal speed change function, and can also work together to perform a differential function.

The casing 1o of the power unit P includes a crankcase 50 that accommodates and supports the crankshaft 20, output shaft 21, etc. of the engine E, and a pair of crankcases 50 that extend rearward from both left and right ends of the crankcase 50 and accommodate and support the automatic transmission MM'. The mission cases 71 and 71' are integrally connected to form a rigid body, and both the mission cases 71 and 71' are arranged substantially horizontally so as to sandwich the front end of the vehicle body frame F from the left and right sides. In this way, both mission cases 71
The space between 11' can be effectively used as a vehicle body space, making the vehicle more compact and contributing to lowering the center of gravity of the power unit P.

Crank case 50 and each transmission case 71°11'
There is a partition wall 72 between them that partitions them in an oil-tight manner, and inside each transmission case γ1, 71' there are each automatic transmission M,
A partition wall γ3 is provided to oil-tightly partition the speed change mechanism including the two boots IJ5B, 59 of M' and the reduction gear mechanism R, and as a lubrication method, each automatic transmission M,
The transmission mechanism M' uses a dry type, and the reduction gear mechanism R uses a wet type.

The casing 70 is divided into several blocks and cast as follows. That is, the central part of the crankcase 50, the intermediate part between the central part and each transmission case 71°11', and the central part of each mission case γ1°11' are divided along a plane perpendicular to the axis of the crankshaft 20. The blocks thus divided are called first to sixth blocks 101 to 7oa from the left in FIG. These blocks 7
01-106 are bolted together between adjacent ones.

17- Second to fifth blocks 70. ~70. Support brackets 14 to γT are integrally provided on the outer surface of the power unit. A single pivot shaft 8 disposed parallel to the crankshaft 20 to connect the P to the vehicle body frame F.
3 is held in place. At that time, each support bracket 74 to TI
The support surfaces of the support caps 19 to 82 are each formed into a semicircular shape that is easy to process and can be brought into close contact with the circumferential surface of the pivot shaft 830, and each through bolt γ8 is formed in order to position and securely fix the pivot shaft 83 to the casing 10. The pivot shaft 83 is passed through. (Then, the second to fifth blocks 102 to
γ0. are also connected to each other by the pivot 83, increasing the connection strength.

Furthermore, each set of support brackets and caps 74°79
; γ5, 80; 76.81; 77.82. In this way, the relatively weak portions of the support brackets 14 to γγ and the plurality of through bolts γ8 are not biased in one direction, and the pivot shaft 83 can be firmly supported in all directions.

The pivot 83 is a support bracket (74) at both outer positions.

On the inside of γ1, it is supported by left and right support plates 1 a and 1 a' of the vehicle body frame F via a pair of left and right Neidhardt type spring devices S f and 5 f'. Since these spring devices Sf*Sf' have the same structure, only the left one Sf will be explained. This spring device Sf is as follows.
As shown in FIG. 7, there is a housing 90 having a spring chamber 91 whose basic shape is a hexagonal cross-sectional shape, and a housing 90 whose basic shape has a hexagonal cross-sectional shape and which is accommodated in the spring chamber 91 so as to be relatively rotatable. and six cylindrical rubber springs 93 filled between the housing 90 and the spring actuating body 92 at the six corners of the spring chamber 91. Fixed by mating or spline fitting. A mounting flange 94 is integrally formed on the outer peripheral surface of the housing 90 and projects over half the circumference thereof.

On the other hand, a semicircular support recess 95 opening toward the front is formed in the support plates 1α, 1a' of the vehicle body frame F, and the housing 90 is fitted into this recess 95 so that its mounting flange 94 is attached to the support plate 1a and ia' with a plurality of bolts 96.

Thus, the power unit P serves as the left and right driving wheels Wf.

When Wf/ swings around the pivot shaft 83 as Wf/ moves up and down, the spring actuating body 92 rotates with respect to the housing 90 and compresses and deforms all the rubber springs 93 at the same time. Drive wheels Wf, Wf due to the repulsive force of 93
' be suspended elastically. By the way, power unit P
As mentioned above, the casing TO constitutes a rigid body and connects both driving wheels F f p F f', so it has a stabilizer function in which the vertical vibration of one driving wheel is suppressed by the other driving wheel. You will be prepared.

In order to damp the vertical motion of both driving wheels Wf+Wi', a hydraulic damper 97 is interposed between each of the support plates 1α, 1a' of the vehicle body frame F and the transmission cases 71, 11'.

The pivot shaft 83 is arranged to pass through the center of gravity of the power unit P. In this way, the moment of inertia of the oscillating system around the pivot shaft 83 consisting of the drive wheels Wf, Wf' and the power unit P can be significantly reduced, and as a result, the road followability of the drive wheels Wf, Wf is improved, and the Neidhardt The load burden on the type spring devices Sf and Sf' is reduced.

Furthermore, in order to reduce the moment of inertia, in the illustrated example, the balancing shafts 22, 21, the starting motor 24, and the water pump 45, which are relatively heavy, are connected to the drive wheel Wf.

It is placed at the front of the engine E to balance the weight of y f/. Note that arranging the water pump 45 at the front of the engine E is convenient because its maintenance can be performed without being obstructed by the vehicle body frame F.

A support tube 100 surrounding the wheel drive shaft 65 is integrally formed on the outer surface of each mission case 71, 71', and an outer tube 101 rotatably supported by this support tube 100 includes:
A pair of king pins 10 whose knuckles 102, which rotatably support the hubs 66 of the corresponding drive wheels Wf, Wf', are coaxially arranged across the swing center of the constant velocity joint 68.
3, and the knuckle 102 is connected to the steering handle 13 via a steering mechanism (not shown).

Therefore, by rotating the steering handle 130 to rotate the knuckle 102 around the kingpin 103, the driving wheel 'fsFf' can be turned.

Further, the knuckle 102 has a corresponding drive wheel Wf.

A back plate 104 of a brake device B (drum type in the illustrated example) of F il is fixed, and this back plate 1
In order to suppress the 040 rotation, a restraining arm 105 protruding from the outer surface of the outer cylinder 101 is connected to the vehicle body frame F via a torque rod 106. Therefore, during braking, the braking torque acting on the back plate 104 is
It is supported by the vehicle body frame F via the outer cylinder 101 and the torque rod 106. In addition, the axis 83 of the power unit P
Relative rotational displacement between the outer tube 101 and the support tube 100 connected to the knuckle 102 is allowed so that the proper alignment of the drive wheels Wf, lVf' is maintained during rotation.

A rear fork 111 is pivotally attached to the rear end of the vehicle body frame F via a pivot shaft 110 so as to be able to swing vertically, and the driven wheel Wr is pivotally supported at the rear end of the rear fork 111 . In order to suspend the rear fork 111, a spring device Sτ having the same structure as the Neidhardt type spring device Sf is installed between the pivot shaft 110 and the rear fork 111.
is interposed.

Further, a hydraulic damper 112 is interposed between the rear fork 111 and the vehicle body frame 1 to damp the vertical movement of the driven wheel Wγ.

As described above, according to the present invention, the shift fork support shaft rotated by the switching input is supported in the casing, and the shift fork boss portion for shifting the switching gear is slidably mounted on the shift fork support shaft. Since the shift drum is integrally connected with the shift drum and has a cam groove that engages with the engagement protrusion protruding from the outer surface of the boss, the shift fork support shaft and the shift drum can be arranged concentrically. This makes it possible to significantly downsize the device, and since there is no need to prepare a bearing for the shift drum connected to the shift fork support shaft, the structure is simple and can be provided at low cost. .

[Brief explanation of drawings]

1 to 7 show an embodiment of the present invention,
Fig. 1 is a perspective view of the separated body frame and power unit of the vehicle, Figs. 2 and 3 are a plan view and side view of the vehicle, Fig. 4 is a side view of the power unit, and Fig. 5 is the power unit. 5A is an enlarged vertical sectional view of the engine part of the same power unit, FIG. 5B is a sectional view taken along the line VB-VB of FIG. 5A, FIG. 5C is a developed view of the body of the shift drum, and FIG. The figure shows VD -VD in Figure 5A.
6 is a side view of the power transmission system of the engine, and FIG. 7 is an enlarged sectional view taken along the line ■-■ in FIG. 5. 33... Switching gear, 3γ... Shift fork support shaft, 38... Shift fork, 38α... Boss portion, 3
8A...Fork part, 39...Shift drum, 39
α, 39b25-... End wall portion, 39. ...Body part, 40...Operating lever, γ0...Casing, γ0α, γob...Bearing, 8γ...Engagement protrusion, 88...Cam groove, 88α, 8
8h...Dead groove, 88c...Slanted groove Patent Applicant: Honda Motor Co., Ltd. 26-11N 1987-194150 (8) JP-A-59-194150 (13)

Claims (1)

[Claims] A shift fork support shaft rotated by a switching input is supported on the casing, a boss portion of a shift fork for shifting the switching gear is slidably fitted onto the shift fork support shaft, and the boss portion is slidably fitted to the shift fork support shaft. A gear switching device that integrally combines a shift drum with a cam groove that engages with an engaging projection protruding from its outer surface.