JPS62168785A - Engine suspension system for motorcycle - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a device for suspending an engine of a motorcycle to a frame.

(Prior Art) As shown in FIG. 6, in a conventional engine suspension system, a pair of opposing brackets 128, 12b are fixed by welding or the like to a cross tube 11 provided between frames. It is widely used to suspend the engine 4 between the brackets 12a and 12b using through bolts 5 inserted through holes provided in the brackets 12a and 12b.

However, the width tolerance of the engine 4 and the brackets 12a, 1
Since there is a width tolerance due to the welding distortion of the brackets 2b, a slight gap often occurs between both side surfaces of the engine 4 and each of the brackets 12a, 12b. Therefore, the brackets 12a, 1
2b is passed through and tightened with the bolt 5, the brackets 12a and 12b tend to curve as shown by the solid line in FIG. 6 and stress is generated. If Q is not sufficient, it is conceivable that the cross tube 11 may crack or the engine 4 may not 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 outer circumferential surface of the bolt 5, the engine 4 may wobble in the radial direction of the bolt 5 if the bolt 5 is not fastened sufficiently.

(Object of the Invention) The present invention has been made against the background of the above-mentioned prior art, and by using a collar that is plastically deformed, there is no assembly stress caused by deformation of the bracket, and the engine is robust and reliable. An object of the present invention is to provide an engine suspension system for a motorcycle that can suspend the engine.

(Structure of the Invention) The present invention relates to an engine suspension system for a motorcycle, in which an engine is suspended between opposing brackets provided on a frame by means of bolts and nuts, and the engine suspension system comprises a side surface of the engine on which the nut is screwed, and a side surface of the engine on which the nut is screwed. A collar is fitted on the outer periphery of the bolt between and in a state where it can be plastically deformed into the bolt ventilation hole of the bracket corresponding to the above, and a recess is formed on the inner wall surface of the bolt through hole, The collar is plastically deformed along the recessed portion by the axial force caused by the tightening of the nut.

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

(Embodiment) An embodiment of the present invention will be described with reference to FIGS. 1 to 3. A pair of left and right main frames 2 are installed diagonally downward and rearward from a head vibrator 1, and near the front end of the main frames 2. , a pair of left and right down tubes 3 are fixed between the rear end portions,
These constitute a frame, and the engine 4 is suspended on this frame via brackets with bolts 5, 6, 7. In addition, the main frame 2 has a seat rail 8.
etc. are fixed, and a rear arm 10 that supports the rear wheel 9 is pivotally supported. A cross tube 11 is hung between the rear ends of the main frame 2, and a pair of opposing brackets 12a and 12b are fixed to the cross tube 11 by welding or the like.

The engine 4 is suspended between these brackets 12a and 12b by a through bolt 5. That is, the bolt 5 is inserted into the bolt through hole (
b) Insert the collar 13 through the through hole inserted into the bolt through hole (b) of the engine 4 and the bolt through hole (c) of the other bracket 12a, and insert it into the threaded part (d) at the tip for screwing the nut. Screw the nut 14 together. Color 13 above
is the outer periphery of the bolt 5, which is in a state where it can be plastically deformed between the nut 14 and the side surface of the engine 4 on the side where the nut is screwed, that is, it is fitted over at least the dimension of the bracket 12a in the vehicle body width direction. , are plastically deformed by the axial force caused by the tightening of the nut 14.

Further, a barrel-shaped recess (or @) 15 is provided on the inner wall surface of the bolt through hole (c) of the bracket 12a that is in contact with the outer peripheral surface of the collar 13, and the collar 13 is plastically deformed along this recess 15. It is now possible to do so. Note that a flange is formed at the end of the collar 13 on the engine 4 side for abutting against the side surface of the engine 4.

In the above configuration, by tightening the nut 14,
The collar 13 has the same effect as when it is plastically deformed and press-fitted along the recess 15, and the engine 4 is tightened with the inner surface (in the vehicle width direction) of one bracket 12b set to 11, and the length of the bolt 5 is tightened. It is securely fixed and suspended both in the longitudinal direction (vehicle width direction) and in the radial direction. Therefore, even if there is a gap between the engine 4 and the brackets 12a and 12b due to tolerances between them,
Given that the engine 4 can be reliably suspended without bending the brackets 12a and 12b, and the dimension between the top surface of the cross tube 11 and the center axis of the through bolt 5 is not large enough. Also, since almost no assembly stress is generated in the brackets 12a, 12b, the cross tube 11 will not be cranked, and the engine 4 will not be tightened sufficiently. In particular, as mentioned above, color 13
By plastically deforming the bracket 12a and the collar 13, wear caused by vibration between the bracket 12a and the collar 13 is prevented, and therefore the suspension state does not change over time.

Next, another embodiment of the present invention will be described with reference to FIGS. 4 and 5. In this embodiment, the opposing brackets 12a
, 12b is an integral part of the bracket 12 together with the base 12G.
This embodiment differs from the above embodiment only in the following points. That is, the intermediate portion Q of the base 12c of the bracket 12 is fixed to the cross tube 11 by welding or the like, and the base 12c
The brackets 12a and 12b are bent with a relatively large curvature at both ends thereof. Bracket 12
Similar to the above, a recess 15 is provided on the inner wall surface of the bolt through hole (c) in A for plastically deforming the collar (not shown) inserted into this through hole. Since it is the same as that, illustration is omitted.

According to this embodiment, even if the dimension m between the center of the bolt through holes (A) and (C) of the brackets 12a and 12b and the top surface of the cross tube 11 is short, the bolt through holes (A) and (C) The dimension n from the center of (c) to the end of the welded portion of the base 12C can be relatively long. Therefore, even if stress is applied to the brackets 12a and 12b due to tightening of the bolts and nuts and the brackets 12a and 12b are bent, the stress exerted on the cross tube 11 for the same amount of displacement is reduced. Therefore, there is no possibility that cracks will occur in the bracket 12 or the cross tube 11 due to stress, and an even more robust suspension structure can be obtained.

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

Further, in the above embodiment, the engine suspension portion using the through bolt 5 has been described, but the same can be applied to the case where the through bolt is used for other bolts 6 or 7.

(Effects of the Invention) As described above, according to the present invention, in a configuration in which an engine is suspended between opposing brackets fixed to a frame by through bolts, a collar is provided in a state where it can be plastically deformed in the bolt through hole of one bracket. is fitted to the outer periphery of the bolt, and a recess 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 generated by tightening the nut. Even if there is a gap between the engine and the bracket due to dimensional tolerances, the engine can be reliably suspended and fixed with almost no deformation of the bracket and therefore almost no assembly stress. It becomes robust without cracking. Furthermore, since the collar is plastically deformed, there will be no wear between the bracket and the collar, and the suspension state will not change over time.

[Brief explanation of drawings]

FIG. 1 is a sectional view of essential parts 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 configuration of the device, and FIG. FIG. 4 is a schematic rear view of a main part according to an embodiment of the present invention, FIG. 5 is a side view of the embodiment shown in FIGS. 2... Main frame (frame), 3... Down tube (frame), 4... Engine, 5... Bolt, 11... Cross tube (frame), 12a, 1
2b...Bracket, 13...Color, 14...
Nut, 15...recess, A11ro, C...bolt through hole. Patent applicant Yamaha Motor Co., Ltd. Representative Patent attorney Etsushi Kotani Patent attorney Chief 1) Masamukai Patent attorney Yasuo Itaya Figure 1 Figure 2

Claims (1)

[Claims] 1. An engine suspension system for a motorcycle in which an engine is suspended by bolts and nuts between opposing brackets provided on a frame, and the outer periphery of the bolt between one side of the engine on which the nut is threaded and the nut. , and the collar is fitted into the bolt through hole of the bracket corresponding to the above in a state where it can be plastically deformed, and a recess is formed on the inner wall surface of the bolt through hole, and the axial force due to tightening of the nut is formed. An engine suspension device for a motorcycle, characterized in that the collar is plastically deformed along the recessed portion.