JP3940279B2 - Power unit mounting device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a power unit mounting device in a rear wheel drive type electric vehicle having a power unit on the rear wheel side.
[0002]
[Prior art]
In a conventional front wheel steering rear wheel drive type vehicle, in particular, an electric golf cart driven by an electric motor, the rear wheel side also includes the power unit itself as described in, for example, Japanese Patent Application Laid-Open No. 4-303478. Including the whole, it is designed to swing in the vertical direction.
[0003]
[Problems to be solved by the invention]
As described above, in a conventional electric vehicle or the like, the suspension mechanism on the rear wheel side including the drive wheels is mounted on a box-type subframe including a trailing arm or the like with a heavy mass unit including an electric motor and a reduction gear. In this state, these are caused to swing in the vertical direction. Therefore, when a vehicle having such a rear suspension mechanism travels in a place with undulations, the behavior on the rear wheel side having a large unsprung mass becomes unstable, and there is a problem that steering stability is impaired. In addition, there is a problem that the subframe itself must be heavy in order to increase the strength and rigidity of the subframe that swings. In order to solve such problems, the power unit is mounted on a sub-frame formed of a pipe-shaped member, and such a sub-frame is attached to the chassis frame while a suspension is formed. An object of the present invention is to provide a subframe-type power unit mounting device in which one end of the swing arm is attached to the subframe via a predetermined bush, thereby reducing the unsprung mass. It is an object (problem) of the invention.
[0004]
[Means for Solving the Problems]
In order to solve the above problems, the following measures are taken in the present invention. That is, according to the first aspect of the present invention, the power unit mounting device in the rear wheel drive type vehicle having the power unit on the rear wheel side is formed in a cross-beam shape as a whole in plan view, This part has a central straight part formed so as to extend linearly in a direction perpendicular to the vehicle body center line for a predetermined period, and is formed at both ends thereof, and attachment points to the chassis frame are provided. And a front cross member having a front mounting portion formed so as to extend forward from the central straight portion in an L shape, and substantially in plan view with respect to the central straight portion of the front cross member. The whole is formed so as to be parallel to each other, and has attachment points to the chassis frame at both ends thereof, and the above-mentioned frame in an elevational view. Has a central horizontal portion which is formed at a predetermined between the horizontal straight line at opposite to the central straight portion of the cement cross member, further, the upper both ends with respect the central horizontal portion is an inverted L-shape A rear cross member having a rear mounting portion formed so as to stand up, and a central straight portion and a central horizontal portion of both cross members, and in the vicinity of the central portion of the vehicle body 2 in parallel with the vehicle body center line. Based on a subframe comprising a connecting member provided so as to connect the central straight portion and the central horizontal portion of the cross members in parallel and in a straight line, the cross-shaped sub near connecting portions between the central straight line portion and the front mounting portion of the front cross member to form a frame, an end portion of one side of the rotation-preventing lateral rod knuckle mounted the rear wheel is attached La Provided with a Raruroddo mounting portion, at the connecting member of the two above, the swing arm mounting portion mounted with left and right rear swing arm is provided, and there is at the center straight line portion and the central horizontal portion of both cross members In the vicinity of the central portion in the vehicle width direction, a configuration was adopted in which a mount portion for mounting a power unit set so as to maintain a mass balance in the left-right direction was provided.
[0005]
By adopting such a configuration, in the present invention, the power unit is mounted at a substantially central portion of the cross-shaped subframe formed in a symmetrical form, and such a subframe is also provided. Since it is attached to the chassis frame, the heavy power unit is mounted on the vehicle in a state where the mass balance is maintained. Therefore, in this vehicle, coupled with the reduction of the unsprung mass around the rear wheel, it is possible to ensure traveling stability on undulating roads and the like.
[0006]
Further, in the present invention, one side of the lateral rod for preventing the rotation of the knuckle to which the rear wheel is attached, in the vicinity of the connecting portion between the central straight portion of the front cross member and the front mounting portion forming the cross beam-shaped subframe. The lateral rod mounting portion to which the end portion of the left and right rear swing arms is attached is provided, and the swing arm mounting portion to which the left and right rear swing arms are attached is provided at the two connecting members. By adopting such a configuration, in the present invention, a heavy power unit is mounted in the vicinity of the center line in the vehicle width direction, the mass balance of the entire vehicle is maintained, and the rear The rear swing arm and lateral rod that restrict the rocking motion of the wheel are attached to the subframe, and the power unit and the rear suspension mechanism are all assembled together in the subframe. Become so. That is, the power unit and the rear suspension mechanism are assembled in an assembled state mainly with the sub-frame, so that the assembly property (assembly property) of the entire vehicle can be improved, and the maintainability of the power unit and the like can be improved. .
[0007]
Next, the invention described in claim 2 will be described. The basic point of this is the same as that of the first aspect. That is, in the present invention, in the power unit mounting apparatus according to claim 1, all the cross members and the connecting members forming the subframe are formed of a steel pipe material having a predetermined circular cross-sectional shape. It was decided to adopt the configuration. By adopting such a configuration, the subframe can be made to exhibit predetermined strength and rigidity after being reduced in weight, thereby reducing the weight of the entire vehicle. It becomes like this. Further, since all the cross members and the connecting members are formed on the basis of the pipe material having the same diameter, the manufacturing cost of the subframe itself can be reduced.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, the present embodiment relates to a cross-beam-shaped sub, which is the basis for mounting a power unit 5 and mounting left and right rear swing arms 7, 7 'and lateral rods 6, 6'. The frame 10 is mainly formed. Then, as shown in FIG. 4, such a subframe 10 is attached to the rear portion of the side frame 91 that forms the chassis frame 9 through attachment points 19 and 29 provided at the four ends thereof. It is something like that.
[0009]
In such a structure, the cross-shaped subframe 10 is linearly shaped for a predetermined period in a direction perpendicular to the vehicle center line, as shown in FIGS. A central straight portion 11 formed so as to extend to each other, and has attachment points 19 to side frames 91 that are formed at both ends thereof and form the chassis frame 9, and the central straight portion A front cross member 1 having a front mounting portion 12 formed so as to extend in an L shape from 11 to the front, and substantially parallel to the central straight portion 11 of the front cross member 1 in plan view. The whole is formed, and has an attachment point 29 to the side frame 91 of the chassis frame 9 at both ends thereof, and in the elevation view, the front There is a central horizontal portion 21 formed in a horizontal straight line for a predetermined time at a position facing the central straight portion 11 of the loss member 1, and both end portions are in an inverted L shape with respect to the central horizontal portion 21. A rear cross member 2 having a rear mounting portion 22 formed so as to rise upward, and two of the cross members 1, 2 at the central straight portion 11 and the central horizontal portion 21 so as to be parallel to the vehicle body center line. The connecting members 3 and 3 'are provided so as to connect the central straight portion 11 and the central horizontal portion 21 of the cross members 1 and 2 in parallel and in a straight line.
[0010]
The cross members 1 and 2 and the connecting members 3 and 3 'forming such a cross-shaped subframe 10 are all formed on the basis of a steel pipe material having a predetermined circular cross-sectional shape. It is what has become. By adopting such a configuration, it is possible to achieve a predetermined strength and rigidity after reducing the weight of the sub-frame 10, thereby reducing the weight of the entire vehicle. . Further, since all the cross members and the connecting members are formed on the basis of the pipe material having the same diameter, the manufacturing cost of the subframe itself can be reduced.
[0011]
In the structure as described above, as shown in FIGS. 1 and 2, a mount for mounting the power unit 5 is provided at the central straight portion of the front cross member 1 or the central horizontal portion 21 of the rear cross member 2. Portions 15 and 25 are provided. In addition, this mount part provided in the front cross member 1 side (15, 15) is in two places in the state corresponding to the mounting apparatus of the power unit 5, especially set so that the mass balance of the left-right direction may be maintained. The one provided on the rear cross member 2 side is provided substantially on the center line of the vehicle body. As a result, as shown in FIG. 2, the power unit 5 is mounted in a state where the left and right balance is maintained at a substantially central portion in the vehicle width direction, so that the running stability of the vehicle can be improved. become.
[0012]
Further, in the vicinity of the connecting portion 121 between the central straight portion 11 and the front mounting portion 12 of the front cross member 1 forming the cross-shaped subframe 10 having such a configuration, as shown in FIGS. Lateral rod mounting portions 16 and 16 'to which one end of lateral rods 6 and 6' for preventing rotation of the rear wheel 8 in a horizontal plane, that is, for preventing rear wheel steering, are provided in a bilaterally symmetrical state. It is like that. The other end of the lateral rods 6 and 6 ′ is connected to a knuckle 88 that supports a wheel (rear wheel) 8 (see FIG. 4).
[0013]
Further, as shown in FIGS. 1 and 3, a swing arm attachment portion 37 to which the rear swing arms 7 and 7 ′ are attached is provided at the connecting members 3 and 3 ′ forming the subframe 10 having such a configuration. 37 'is provided. The rear swing arms 7 and 7 'are attached to the swing arm attaching portions 37 and 37' through a rubber bush. As shown in FIG. 4, a knuckle 88 is connected to the front ends of the rear swing arms 7 and 7 ′, and a wheel (rear wheel) 8 is attached to the knuckle 88. It is what.
[0014]
Thus, in the present embodiment, the rear swing arm 7 that forms the rear suspension mechanism and has the heavy mass power unit 5 mounted substantially at the center of the sub-frame 10 having a cross-beam shape. 7 'and the lateral rods 6 and 6' are attached, and the power unit 5 and the rear suspension mechanism assembled in this manner are attached to the rear portion of the chassis frame 9, so that the power unit 5 and the rear suspension are attached. The efficiency of attaching the mechanism to the chassis frame 9 can be improved. In addition, the power unit 5 can be attached and detached through the subframe 10, and the power unit 5 can be efficiently maintained.
[0015]
【The invention's effect】
According to the present invention, a power unit mounting device in a rear wheel drive type vehicle having a power unit on the rear wheel side is formed in a cross-beam shape as a whole in a plan view, and the center portion in the vehicle width direction is the center of the vehicle body. A central straight portion formed so as to extend linearly in a direction perpendicular to the line for a predetermined period, and formed at both ends thereof, having attachment points to the chassis frame, and A front cross member having a front mounting portion formed so as to extend in an L shape forward from the central straight portion, and the whole so as to be substantially parallel to the central straight portion of the front cross member in plan view And has attachment points to the chassis frame at both ends thereof, and the front cross member of the front cross member in the elevational view. It has a central horizontal portion formed in a horizontal straight line for a predetermined time at a position facing the central straight portion, and further, both end portions are formed to rise upward in an inverted L shape with reference to the central horizontal portion. A rear cross member having a rear mounting portion, and the center of both cross members in parallel and linearly so as to be parallel to the vehicle center line at the central straight portion and the central horizontal portion of both cross members. For mounting a power unit near the center of both cross members forming such a cross-shaped subframe on the basis of a subframe comprising a connecting member provided so as to connect the straight portion and the central horizontal portion. Therefore, the power unit is mounted almost at the center of the cross-beam shaped subframe formed in a symmetrical form. Together, such sub-frame becomes possible to be attached to the chassis frame, adapted to be mounted on the vehicle in a state heavy power unit of mass of the mass balance is maintained. As a result, in this vehicle, traveling stability on undulating roads and the like has been secured in combination with reduction of unsprung mass around the rear wheels.
[0016]
Also, in the present invention, a lateral rod provided for preventing the rotation of a knuckle to which a rear wheel is attached, in the vicinity of a connecting portion between the central straight portion of the front cross member and the front mounting portion forming the cross beam-shaped subframe. The lateral rod mounting portion to which the one end portion is mounted is provided, and the swing arm mounting portion to which the left and right rear swing arms are mounted is provided at the two connecting members. Therefore, a heavy mass power unit is mounted near the center line in the vehicle width direction, the mass balance of the entire vehicle is maintained, and the rear swing arm that regulates the swinging motion of the rear wheels and Lateral rods will be attached to the sub-frame, and the power unit and rear suspension mechanism And adapted to be mounted in a state gathered integrally on all for the sub-frame. As a result, the power unit and the rear suspension mechanism can be assembled in an assembly state based on the sub-frame, thereby improving the assembly property (assembly property) of the entire vehicle and further improving the maintainability of the power unit and the like. I can do it now.
[0017]
Further, in the present invention, since all the cross members and the connecting members forming the sub frame are formed of a steel pipe material having a predetermined circular cross-sectional shape, The weight of the frame can be reduced and the predetermined strength and rigidity can be exerted, thereby reducing the weight of the entire vehicle. In addition, since all the cross members and the connecting members are formed on the basis of pipe materials having the same diameter, the manufacturing cost of the subframe itself can be reduced.
[Brief description of the drawings]
FIG. 1 is a plan view showing an overall configuration of the present invention.
FIG. 2 is a rear view showing the overall configuration of the present invention.
FIG. 3 is a side view showing the overall configuration of the present invention.
FIG. 4 is a plan view showing a state in which a subframe constituting the main part of the present invention is attached to a chassis frame.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Front cross member 11 Center straight part 12 Front attachment part 121 Connection part 15 Mount part 16 Lateral rod attachment part 16 'Lateral rod attachment part 19 Attachment point 2 Rear cross member 21 Center horizontal part 22 Back attachment part 25 Mount part 29 Attachment point 3 Connecting member 3 'Connecting member 37 Swing arm mounting portion 37' Swing arm mounting portion 5 Power unit 6 Lateral rod 6 'Lateral rod 7 Rear swing arm 7' Rear swing arm 8 Wheel (rear wheel)
88 knuckle 9 chassis frame 91 side frame 10 subframe

Claims (2)

The central straight part formed so that the whole is formed in a cross-beam shape in plan view, and the part of the central part in the vehicle width direction extends linearly for a predetermined time in a direction perpendicular to the vehicle center line. And having a front attachment portion formed at both ends thereof, having attachment points to the chassis frame, and extending in an L shape forward from the central straight portion. The front cross member is formed so as to be substantially parallel to the central straight portion of the front cross member in plan view, and has attachment points to the chassis frame at both ends. together, has a central horizontal portion which is formed at a predetermined between the horizontal straight line at opposite to the central straight portion of the front cross member in elevation view, further, reference the central horizontal portion Rear cross member, near the center where the A and the vehicle body of the central straight line portion and the central horizontal portion of both cross members having a rear attachment portion both end portions are formed so as to rise upward in inverted L-shaped and And a connecting member provided so as to connect between the central linear portion and the central horizontal portion of the cross members in parallel and linearly so as to be parallel to the vehicle body center line. Based on the subframe , one side of the lateral rod for preventing the rotation of the knuckle to which the rear wheel is attached, in the vicinity of the connecting portion between the central straight portion of the front cross member and the front mounting portion forming such a cross- shaped subframe. A swing rod mounting portion to which the left and right rear swing arms can be mounted at the two connecting members is provided. Provided, and, in the vicinity of the vehicle width direction central portion is a in place of the central straight line portion and the central horizontal portion of both cross members, to provide a mounting portion for the set power unit mounted to to keep the weight balance between the left and right directions A power unit mounting device characterized by that. 2. The power unit mounting apparatus according to claim 1 , wherein all of the cross members and the connecting members forming the sub-frame are formed on the basis of a steel pipe material having a predetermined circular cross-sectional shape. Power unit mounted device.

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