JPH0688552B2 - Motorcycle engine suspension - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a device for suspending a motorcycle engine on a frame.

(Prior Art) As a conventional engine suspension device, as shown in FIG. 6, a cross tube provided between frames is provided.
A pair of opposed brackets 12a and 12b are fixed to 11 by welding or the like, and an engine 4 is widely used by suspending the engine 4 between the brackets 12a and 12b by a through bolt 5 which is inserted through holes provided in the brackets 12 and 12b. Has been.

However, since there is a width tolerance of the engine 4 and a width tolerance due to welding distortion of the brackets 12a, 12b, a slight gap often occurs between both side surfaces of the engine 4 and the brackets 12a, 12b. Therefore, through the brackets 12a, 12b through bolt 5
When tightened by, the brackets 12a and 12b tend to bend as shown by the solid line in FIG. 6 to generate stress,
When the dimension l between the upper surface of the cross tube 11 and the central axis of the through bolt 5 cannot be sufficiently taken, it is considered that the cross tube 11 is cracked or the engine 4 cannot be completely tightened. .

Further, if there is play between the inner wall surface of the bolt through hole such as the bracket 12a and the inner peripheral surface of the bolt 5, the engine 4 may rattle in the radial direction of the bolt 5 if the fastening is not sufficient.

(Object of the Invention) The present invention has been made against the background of the above-mentioned conventional technology, and by using a plastically deformable collar, the assembly stress due to the deformation of the bracket does not occur, and the engine is robust and reliable. An object of the present invention is to provide an engine suspension device for a motorcycle capable of suspending a vehicle.

(Structure of the Invention) The present invention relates to an engine suspension device for a motorcycle, in which an engine is suspended between opposing brackets provided on a frame by a bolt and a nut, and one side surface of the engine on a screw side of the nut and the nut. The collar is fitted on the outer circumference of the bolt between and in the bolt through hole of the bracket corresponding to the above in a state of being plastically deformable, and a recess is formed on the inner wall surface of the bolt through hole. The collar is plastically deformed along the recess by the axial force due to the tightening of the nut.

With this configuration, the collar is press-fitted along the concave portion of the bolt through hole of the bracket, and the engine can be securely tightened without bending the bracket.

(Embodiment) An embodiment of the present invention will be described with reference to FIG. 1 to FIG. 3. A pair of left and right main frames 2 are extended obliquely downward and rearward from the head pipe 1, and the main frame 2 and the vicinity of the front end thereof are A pair of left and right down tubes 3 are fixed between the rear end portions, and a frame is constituted by these, and an engine 4 is suspended by bolts 5, 6, 7 via a bracket on this frame. In addition, a seat rail 8 is provided on the main frame 2.
A rear arm 10 for supporting the rear wheel 9 is pivotally supported. A cross tube 11 is stretched between the rear end portions of the main frame 2, and a pair of opposed brackets 12a and 12b are fixed to the cross tube 11 by welding or the like.

The engine 4 is suspended by through bolts 5 between the brackets 12a and 12b. That is, the bolt 5 is attached from one side in the width direction of the vehicle body to the bolt through hole (a) of the bracket 12b and the bolt through hole (b) of the engine 4 and the other bracket 12
The nut (14) is screwed into the threaded portion (d) for screwing the nut at the tip of the collar (13) which is inserted through the through hole of the collar (13) which is inserted into the bolt through hole (c) of (a). The collar 13 is the outer periphery of the bolt 5, and is a side surface of the engine 4 on the nut screw side and the nut.
The bracket 12a and the bracket 12a are fitted in a state in which they can be plastically deformed, that is, at least the size of the bracket 12a in the width direction of the vehicle body is fitted, and the nuts 14 are plastically deformed by the axial force.
Further, a barrel-shaped recess (or groove) 15 is provided on the inner wall surface of the bolt through hole (C) of the bracket 12a, which is in contact with the outer peripheral surface of the collar 13, and the collar 13 is plastically deformed along the recess 15. It is supposed to be done. In addition, color
A flange for contacting the side surface of the engine 4 is formed at the end of 13 on the engine 4 side.

In the above configuration, by tightening the nut 14, the same action as when the collar 13 is plastically deformed along the recess 15 and press-fitted is achieved, and the engine 4 has the inner surface of the one bracket 12b (in the width direction of the vehicle body). ) As a reference, and is securely fixed and suspended in both the length direction (vehicle body width direction) and the radial direction of the bolt 5. Therefore, due to the tolerance between the engine 4 and the brackets 12a, 12b, etc., even if there is a gap between them, the bracket 12
Even if the engine 4 can be reliably suspended with almost no bending of the a and 12b, and the dimensions of the upper surface of the cross tube 11 and the central axis of the through bolt 5 cannot be sufficiently taken. Since the assembling stress is hardly generated in the brackets 12a and 12b, the cross tube 11 is not cracked and the engine 4 cannot be tightened sufficiently. In particular,
By plastically deforming the collar 13 as described above, abrasion and the like due to vibration between the bracket 12a and the collar 13 is eliminated, and therefore the suspension state does not change with time.

Next, another embodiment of the present invention will be described with reference to FIGS. In this embodiment, the opposing brackets 12a, 12 are
It differs from the above-described embodiment only in that b is an integral bracket 12 together with the base 12c. Ie bracket 12
Is fixed to the cross tube 11 by welding or the like at an intermediate portion 1 of the base portion 12c.
The brackets 12a and 12b are erected by being bent with a large curvature. Similarly to the above, the inner wall surface of the bolt through hole (c) of the bracket 12a is provided with a recess 15 for plastically deforming a collar (not shown) inserted into this through hole. Since it is the same as the above, illustration is omitted.

According to this embodiment, even if the dimension m between the centers of the bolt through holes (a) and (c) of the brackets 12a and 12b and the upper surface of the cross tube 11 is short, the bolt through holes (a) and The dimension n from the center of (c) to the end of the welded portion of the base portion 12c can be relatively long. Therefore, even if the brackets 12a and 12b are stressed and bent due to the tightening of the bolts and nuts, the stress exerted on the cross tube 11 with respect to the same displacement amount becomes small. Because of this, the bracket
There is no risk of cracks occurring in the 12 and the cross tube 11 due to stress, and a more robust suspension structure can be obtained.

In each of the above-described embodiments, by forming a large number of irregularities on the outer peripheral surface of the collar 13 by knurling, an even greater press-fitting effect can be obtained when plastically deformed.

Further, in the above-described embodiment, the engine suspension portion by the through bolt 5 is described, but the same can be applied to the other bolts 6 or 7 when the through bolt is used.

As described above, according to the present invention, in the configuration in which the engine is suspended by the through bolt between the opposed brackets fixed to the frame, the collar is plastically deformable in the bolt through hole of one bracket. Is fitted to the outer circumference of the bolt, and a concave portion for plastic deformation of the collar is provided on the inner wall surface of the bolt through hole, and the collar is plastically deformed by the axial force due to the tightening of the nut, so that the engine etc. Even if there is a clearance between the engine and the bracket due to the dimensional tolerance, the bracket can be securely suspended and fixed with almost no deformation of the bracket, and thus with almost no assembly stress. It will be robust without cracking. Moreover, since the collar is plastically deformed, abrasion or the like does not occur between the bracket and the collar, and the suspended state does not change with time.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part of an embodiment of an engine suspension system for a motorcycle according to the present invention, FIG. 2 is a side view showing the overall construction of the system, and FIG. 3 is a view taken in the direction of arrow A in FIG. FIG. 4 is a schematic rear view of an essential part according to another embodiment of the present invention, FIG. 5 is a side view of the embodiment of FIG. 4, and FIG. 6 is a sectional view showing an example of a conventional suspension system. 2 ... Main frame (frame), 3 ... Down tube (frame), 4 ... Engine, 5 ... Bolt, 11 ...
Cross tube (frame), 12a, 12b …… bracket, 13 …… collar, 14 …… nut, 15 …… recess, a,
B, C ... Bolt through hole.

Claims (1)

[Claims] 1. An engine suspension system for a motorcycle in which an engine is suspended between bolts and nuts provided between opposing brackets provided on a frame, the engine suspension system comprising: Around the bolt, and
The collar is fitted into the bolt through hole of the bracket corresponding to the above in a state of being plastically deformable, and a recess is formed on the inner wall surface of the bolt through hole, and the collar is formed by the axial force due to the tightening of the nut. An engine suspension system for a motorcycle, wherein the engine is plastically deformed along the recess.