JPS59199328A - Transmission case - Google Patents

Abstract

PURPOSE:To obtain a transmission case that is lightweight and high in rigidity, by making a case body of a transmission case for housing a wrapping transmission gear that connects between input and output shafts into a seamless cylinder, and closing the opposite open surfaces of the cylinder by lids detachably. CONSTITUTION:A power unit P is swingably attached about a pivot shaft 83 at the forward end of a car body frame F and rotates a pair of right and left driving wheels Wf. The power unit P consists of an engine E and a pair of right and left belt type automatic transmissions M arranged on opposite sides of the rear of the engine E. The casing 70 of the power unit P consists of a crank case 50 and a transmission case 7a extending rearward from the right and left sides thereof. The transmission case 71 has a cylindrical case main body 72 diverged from an input shaft 52 toward an output shaft 61, and the slanted open surfaces 72a, 72b formed at the opposite ends thereof are closed by lid bodies 73a, 73b respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a transmission case in which a winding connecting an input shaft and an output shaft parallel to each other accommodates a transmission device, and particularly to a cast transmission case.

Conventional transmission cases of this type are wrapped around belts, etc. ) It is cast in two parts on the left and right along the running surface of the bearing member, and the windings are tied together after the transmission is housed.In order to compensate for the decrease in rigidity of the transmission case due to such division, each part is Since it is necessary to form a thick wall, it is heavy (some people dislike it).

Therefore, an object of the present invention is to provide a lightweight and highly rigid transmission case in which the main part of the case can be cast without being split, and its characteristics are as follows: The transmission case has a cylindrical shape with a wide end and a small size (both have a seamless case body with the end face on the output shaft side as an open face, and a lid body that is tied to the case body so as to close the open face). It is located where it is configured.

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 drive wheels IFf at the front of a vehicle body frame F.

Wf', a power unit P for driving these, and one driven wheel IFr are respectively disposed at the rear thereof.

The vehicle body frame F has support plates ia, ia on 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',
Three inverted U-shaped roll pars connected to the center and rear parts 7.8. The front roll par 7, the frontmost cross member 2, and the left and right support plates 1α, 1α′ are connected via a cross-shaped reinforcing member 1o, and the central roll par 8 and rear roll par 9 is connected at the top via a reinforcing member 11. Steering handle 1 in the center of the front roll par 7
A steering column supporting 3 is attached.

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 reinforcement members 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 is installed for these back seats 14. Z, 15α is the center rollpa 8
and iJ rear roll par 9Kl are arranged substantially along each other. 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 FIGS. 4 to 6, the power unit P includes an engine E, and a pair of left and right windings disposed on both sides of the rear thereof, which are belt type automatic transmissions M and Ml as transmission devices.

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 and a pump drive shaft 23 are each disposed parallel to the crankshaft 20, and a starter motor 24 is disposed adjacent to the left end of the crankshaft 20. A generator 25 is installed on the left end of the crankshaft 20, and a centrifugal automatic starting clutch 26 is installed on the right end of the crankshaft 20. Between the clutch 26 and the output shaft 21, there is a speed reduction device with a forward/reverse switching function. 27 are provided.

This device 27 includes a small-diameter drive gear 28 fixed to the output member of the clutch 26, and a large-diameter relay gear 29 rotatably supported by the output shaft 21 and constantly engaged with the drive gear 28 via an idle gear 28'. , the first idle gear 3 with a diameter of
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. 29, a dog clutch consisting of a dog 34 and a dog hole 35 that can engage with each other is provided on the switching gear 33 and the relay gear 29, and in the backward position, the dog clutch 34, 35 is released and the switching is performed. Gear 33 is the second
It is designed to mesh with the idle gear 32.

When the switching gear 33 is placed in the forward position, the 200 rotations of the crankshaft are transmitted to the output shaft 21 through the starting clutch 26, drive gear 28, idle gear 28', relay gear 29, and switching gear 33 in order. This can be rotated in the normal direction to move the vehicle forward. Furthermore, if the switching gear 33 is shifted to the reverse position, the above rotation is controlled by the starting clutch 26,
The deceleration is transmitted to the output shaft 21 through the drive gear 28, the idle gear 28', the first idle gear 31, the second idle gear 32, and the switching gear 33 in order, and is reversed to drive the vehicle backward.

In order to provide the switching gear 33 with the above switching, a gear switching device is provided as follows.

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, and operational input from a gear shift lever (not shown) is applied to the shift fork support shaft 37 via the operating lever 40.

A boss portion 38a of the shift fork 38 is slidably fitted into the shift fork support shaft 3γ, and the shift fork 38
The fork portion 3El is connected to the boss portion 33 of the switching gear 33.
The boss portion 33α is engaged with an annular groove 36 provided on the outer periphery of α so as to sandwich the boss portion 33α.

In addition, a shift drum 39 is attached to the shift fork support shaft 30.
are integrally combined. The shift drum 39 is made of a press, and has a pair of left and right end walls 3 that are penetrated and supported by the shift fork support shaft 37 at positions adjacent to the bearings 70α and 70b.
9a, 39/) and both end walls 39a, 39h,
It also includes a body portion 39C that surrounds approximately half the circumference of the boss portion 38α of the shift fork 38 concentrically with the shift fork support shaft 3γ. Right end wall portion 39b of this shift drum 39
The fitting part between the and the shift fork support shaft 37 has an occluded cross-section, and both parts 37 and 39 can rotate together, but the shaft is rotated in the axial direction by both bearing parts 70α and 70b. Movement is prevented.

A cam groove 88 is provided in the body portion 39c of the shift drum 39, and an engaging protrusion 87 that engages with the cam groove 88 is integrally formed on the outer surface of the boss portion 38α of the shift fork 38.

Thus, when the switching gear 33 is placed in the neutral position, the shift fork 38 occupies the center position of the shift fork support shaft 37. Therefore, when the operating lever 40 is operated to rotate the shift drum 39 in one direction or the other, the shift fork 38 is displaced to the right or left via the engagement protrusion 87 due to the guiding action of the cam groove 88. , the switching gear 33 can be shifted to the forward or reverse position.

The output shaft 21 is composed of a hollow shaft, and the input shafts 52° 52 of the left and right belt type automatic transmissions M and Ml are installed in the hollow part.
0 inner end portions protrude from the left and right, and these input shafts 5
2.52 is connected to the output shaft 21 via a differential gear DJ. A differential case 53 of the differential device Df is integrally formed in the middle part of the output shaft 21, and a pinion shaft 55 supporting pinions 54 and 54 is attached to this differential case 53, as in a general differential device. A pair of left and right side gears 56, 56 meshing with the input shafts 54, 54 are spline-coupled to the left and right input shafts 52, 52, respectively. Therefore, the left and right automatic transmissions M, Ml are connected in parallel to the output shaft 21 of the engine E via the differential device Df, and the left and right drive wheels Wj, If' are respectively concatenated.

The connection structure will be described later.

Since the left and right automatic transmissions M and ltP have the same structure, only the structure of the left one M will be described. Input shaft 5
A variable diameter drive pulley 58 is located at the end of the output shaft 6.
A variable diameter driven pulley 59 is attached to each of the drive pulleys 1 and 1.
An endless belt 60 is stretched between both boos IJ 58 and 59. The drive pulley 58 has a centrifugal mechanism 62 that operates to increase its effective diameter as its rotational speed increases.
On the other hand, the driven pulley 59 is equipped with a spring 63 that acts to constantly increase its effective diameter, and the interaction between the centrifugal mechanism 62 and the spring 63 allows the input shaft 52 and the output shaft 61 to change the gear ratio. The rotational speed of the shaft 520 is automatically decreased as the rotational speed of the shaft 520 increases.

A wheel drive shaft 65 is spline-coupled to the outer end of the output shaft 61, and an axle 67 fixed to a hub 66 of a drive wheel Wf is connected to this wheel drive shaft 65 via a constant velocity joy/toro 8.

When the power of the engine E is output from the output shaft 21, the output torque is transmitted to the differential case 53, the pinion shaft 55, the pinions 54, 54, and the left and right side gears 56.
56, the rotational torque of each input shaft 52 is distributed to the left and right input shafts 52.
0, the signal is transmitted to the corresponding drive wheel ff or ffj via the driven pulley 59, the output shaft 61, and the wheel drive shaft 65 to drive the corresponding drive wheel ff or ffj.

If the number of revolutions of each input shaft 520 also increases as the engine number of revolutions increases, the gear ratio between the driver and the output shafts 52, 61 decreases due to the interaction of the centrifugal mechanism 62 and the spring 63.
Output shaft 61 and drive wheel Wf.

It comes to be driven at a high speed of F f/.

Then, when the vehicle is traveling straight, both driving wheels Ff.

If F f / is rotating at the same speed and there is a difference in gear ratio between both automatic transmissions M and M1, the differential function of the differential device Df will shift the left and right input shafts at 52 degrees. 5
A rotational speed difference is given to the two driving wheels Wf and Wf/, that is, the difference in the transmission ratio is absorbed, and both driving wheels Wf and Wf/ can continue to rotate at the same speed.

Also, when the vehicle turns, the differential device Df exerts its differential function to provide a difference in rotational speed between the left and right input shafts 52, 52, but at the same time, both automatic transmissions M and M' also work together to create a difference in rotational speed. Demonstrates dynamic functions. That is, if the rotational speed of the input shaft 520 on the inner wheel side of the turning path, for example, on the left side, decreases, in the left automatic transmission M, the gear ratio between the driver and the output shaft 52°61 increases; For example, since the rotation speed of the input shaft 520 on the right side increases, in the automatic transmission M' on the right side, the rotation speed of the input shaft 520 increases.
The gear ratio between 2.61 and 2.61 is reduced, and these give the left and right drive wheels Wf, 1ift a rotational speed difference according to the length of their respective turning paths, and therefore the differential gear D
The differential load on f is reduced.

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 22a is connected to the crankshaft 2
0, a pair of crank webs 20a, 20. It is installed at a position where it enters between
The primary inertia force balancing action of the engine E by the weight 22a is well known, so its explanation will be omitted.

The pump drive shaft 23 is driven by the crankshaft 20 via a chain transmission 43. A lubricating oil 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, a rotating shaft 47 having an impeller 46 of the water pump 45 is connected to the pump drive shaft 23 via a removable joint 48, and a pump housing 49 that supports the rotating shaft 47 and houses the impeller 46 is It is fixed to the crankcase 50 of the engine 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.

In addition, when the engine E is an air-cooled type, the water pump 45 is removed in this way, and the opening of the crankcase 50 after the pump crank 49 is covered with a suitable blind cover.

The starting motor 24 is disposed in a space 64 between the engine E and one automatic transmission M, and is supported by a casing 70 via a support member 69. The output gear 24α of the starting motor 24 is connected to a reduction gear 89 on the crankshaft 20 via a large-diameter gear 84, a connecting shaft 85, and a small-diameter gear 86, which are arranged to straddle the generator 25 from the left and right sides. The gear 89 and the crankshaft 20 are connected via an overrunning clutch 98 that can transmit driving force from the gear 89 to the crankshaft 20 in only one direction. By doing so, the crankshaft 20 can be cranked by the starting motor 24 from outside the generator 25 at the time of starting.

The casing 70 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 an automatic transmission M that extends rearward from both left and right ends of the crankcase 50.

A pair of transmission cases 71 according to the present invention that accommodate and support M'
．． 71' are integrally connected to form a rigid body, and both transmission cases 71 and 71' are arranged substantially horizontally so as to sandwich the front end portion of the vehicle body frame F from the left and right sides. In this way, the space between the two transmission cases 71, 71' can be effectively used as a vehicle body space, making it possible to make the vehicle more compact and contributing to lowering the center of gravity of the power unit P.

The casing 70 is divided into several blocks and cast as follows. That is, it is divided along a plane perpendicular to the axis of the crankshaft 20 at the center of the crankcase 50 and at intermediate portions between the center and each transmission case 71, 71'.
The parts divided in this way are shown in the first row from the left in Figure 5.
~4th block 70, ~704. These blocks 701-704 are bolted together between adjacent ones.

Support brackets 74 to 77 are integrally provided on the outer surfaces of the first to fourth blocks 70□ to 704, respectively, and support brackets 74 to 77 and support caps each connected to these via through bolts 78. 79 to 82, there is a single pivot shaft 8 disposed parallel to the crankshaft 20 in order to connect the power unit P to the vehicle body frame F.
3 is held. At that time, each support bracket 74 to 77
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 70. The pivot shaft 83 is passed through. Thus, the first to fourth blocks 70. ~
704 are also connected to each other by a pivot 83, increasing the strength of the connection.

Furthermore, each set of support brackets and caps 74°79
; 75, 80 near 6.81; 77.82 mating surfaces are shifted in phase from each other in the circumferential direction of the pivot shaft 830. In this way, the relatively weak parts of the support brackets 74 to 77 and the plurality of through bolts 780 are not biased in one direction, and can firmly support the pivot shaft 83 in all directions.

The pivot 83 is connected to a pair of left and right Knightnold spring devices S on the inside of the support brackets 74 and 77 at both outer positions.
f, Sf/ to the left and right support plates 1α of the vehicle body frame F
, 1a'. These spring devices Sf, Sf'
Since they have the same structure, only the one on the left Sf will be explained. As shown in FIG. , a spring operating body 92 whose basic shape has a hexagonal cross-sectional shape and is accommodated in the spring chamber 91 so as to be relatively rotatable; The spring actuating body 92 is fixed to the pivot shaft 83 by face fitting or spline fitting. housing 90
A mounting flange 9 is provided on the outer circumferential surface of the
4 are integrally formed.

On the other hand, the support plates ia, l a,' of the vehicle body hump F
A semi-cylindrical support portion 95 that opens toward the front is formed in the recess 95, and the housing 90 is fitted into the recess 95, and its mounting flange 94 is fixed to the support plates 1a and 1a' with a plurality of bolts 96. be done.

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

When F f / swings around the pivot shaft 83 as it moves up and down, the spring actuating body 92 rotates relative to the housing 90 and applies compressive deformation to all the rubber springs 93 at the same time, and the rubber generated due to the deformation Due to the repulsive force of the spring 93, the drive wheel Wf,
Wfl is elastically suspended. By the way, the casing 70 of the power unit P constitutes a rigid body as described above and connects the two driving wheels If, IfI. It will have functions.

In order to damp the vertical motion of both driving wheels Trlf and Wfl, a hydraulic pumper 97 is interposed between each of the support plates la and ia' of the vehicle body frame F and the transmission cases γ1 and 71'.

Each transmission case 71 , 71 ′ has a seamless case body 72 that has a cylindrical shape that widens from the input shaft 52 side to the output shaft 61 side, and the front end surface of this case body 12 is located at the front of the vehicle. This opening surface 72 (Z) is closed by a front lid 73α that is removably fixed to the case body 72 with bolts 99. The rear end surface of 72 is a diagonal open surface 72b that opens toward the rear and inside of the vehicle,
This open surface 72b is closed by a rear lid 73b that is removably fixed to the case body 72 with bolts 89'.

The case body 72 is cast by placing cores corresponding to the internal space and the front and rear open surfaces 72a and 72/I in a mold, and the case body 72 has a seam. Since it spreads toward at least the open surface 721) at the rear end, the core can be easily released from the mold. Moreover, since the driven pulley 59 with a sufficiently large diameter can be accommodated on the wide output side, a sufficient reduction ratio can be provided to the transmissions M1, M/.

In addition, assembly and maintenance of the transmissions M and M' are performed using the front and rear lids 73.
This is done from the open surfaces 72α and 72h by removing α and γ3b, but especially if these open surfaces γ2α and 72b are formed obliquely as described above, the above-mentioned assembly work can be performed from two directions: the front-rear direction and the left-right direction. This results in improved workability.

A wheel drive shaft 6 is provided on the outer surface of each transmission case 71, 71'.
A support cylinder 100 surrounding the outer cylinder 100 is integrally formed, and an outer cylinder 101 rotatably supported by the support cylinder 100 has a knuckle 102 rotatably supporting the hub 66 of the corresponding drive wheel Wf, Wf/. are connected via a pair of king pins 103 coaxially arranged to sandwich the swing center of the constant velocity joint 68, and the knuckle 102 is connected to the steering handle 13 via a steering mechanism (not shown). Therefore, by rotating the steering handle 130 times, the knuckle 10
2 around the king pin 103, the drive wheel 1rl
f, Ir1fl can be converted.

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

A backplate 104 of a brake device B (drum type in the illustrated example) of F fr is fixed, and this backplate 1
04, 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 1o4 is the knuckle 102,
It is supported by the vehicle body frame F via the outer cylinder 1o1 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 10o connected to the knuckle 102 is allowed so that the proper alignment of the drive wheels Wf, ffl is maintained during rotation around the knuckle 102.

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 Wγ is pivotally supported at the rear end of the rear fork 111 . In order to suspend the rear fork 111, a spring device Sr 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 foot frame F to damp the vertical movement of the driven wheel Wγ.

As described above, according to the present invention, the winding is a case in which the transmission case of the transmission device has a cylindrical shape that widens from the input shaft side toward the output shaft side, and is small (in both cases, the transmission case is a joint with an open end face on the output shaft side). Since the case body is composed of a blank case body and a lid that is attached to the case body so as to close the open face, when casting the case body, the core from the open face can be removed without disassembling the case body. can be released from the mold, and therefore a seamless case body can be easily cast.Also, since there is no seam, high rigidity can be obtained even if the case body is made thin, resulting in a lighter transmission case. However, since a large-diameter driven pulley or other driven wheels can be installed on the wide output shaft side of the transmission case body, the reduction ratio of the transmission device can be freely selected for winding. can do.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a perspective view of a separated body frame and power unit of a vehicle;
Figures 2 and 3 are a plan view and a side view of the vehicle, Figure 4 is a side view of the power unit, Figure 5 is a longitudinal cross-sectional plan view of the main parts of the power unit, and Figure 5A is an enlarged view of the engine part of the power unit. 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 W--■ in FIG. 5. M, M'... Belt type automatic transmission as a wrap transmission device 52... Input shaft, 61... Output shaft, 71, 71'
...Transmission case, 72...Case body, 72b...
・Open surface, 73h...Lid patent applicant Honda Motor Co., Ltd.

Claims (1)

[Claims] In the transmission case that houses the transmission device, the winding that connects the input shaft and the output shaft that are parallel to each other has a cylindrical shape that widens from the input shaft side toward the output shaft side, and has at least an open end surface on the output shaft side. What is claimed is: 1. A power transmission case comprising: a seamless case body; and a lid body fastened to the case body so as to close the open surface.