Guard structure for vehicle seat lock

A guard structure for a vehicle seat lock includes a cable 54 operatively connecting between a seat locking mechanism (49) for a vehicle seat and a key device (51) adapted to be actuated by a key. The guard structure also includes a guard body (81) for blocking an access from outside of a vehicle body to the cable (54).

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a guard structure employed in a vehicle seat lock for preventing a cable, used to connect between a seat locking mechanism and a key device adapted to be actuated by a key, from being forcibly operated from outside by the use of a tool.

2. Description of the Prior Art

In most motorcycles, a utility compartment and/or an electronic control appliance are disposed beneath a seat assembly and, therefore, the seat assembly is removably mounted on a vehicle body in order to enable access to the utility compartment and/or the electronic control appliance. In order to prevent the seat assembly from being removed by an unauthorized person having no key, the seat assembly is mounted on the vehicle body through a seat locking mechanism. Upon turn of a key inserted into a key device, the seat locking mechanism can be unlocked through a cable. See, for example, the Japanese Laid-open Patent Publication No. 2004 -11257 , published Jan. 15, 2003.

However, the conventional seat locking mechanism has a problem that if a person having no key inserts an elongated flexible tool such as a wire through a gap present around the key device or the cable to hitch the cable, the sheet locking mechanism can be unlocked.

SUMMARY OF THE INVENTION

The present invention has been made to substantially eliminate the foregoing problems and inconveniences inherent in the conventional vehicle seat lock and is intended to provide a guard structure for the vehicle seat lock, which is effective to prevent a seat locking mechanism from being unlocked without turn of a key.

In order to accomplish the foregoing object of the present invention, there is provided a guard structure for a vehicle seat lock, which includes a cable operatively connecting between a seat locking mechanism for a vehicle seat and a key device adapted to be actuated by a key. The guard structure further includes a guard body for blocking an access from outside of a vehicle body to the cable. It is to be noted that the term “vehicle body” used hereinabove and hereinafter is intended to encompass a motor vehicle structure including a vehicle frame structure and a mechanical skeleton of the vehicle fixed on the vehicle frame such as a fairing, side covers and a tail cover.

According to the present invention, even if an attempt is made to insert a tool such as a wire through a gap present around the key device or the cable so as to make access to the cable, this tool can be barred by the guard body and is therefore blocked from reaching the cable. Because of this, it is possible to prevent the seat locking mechanism from being unexpectedly unlocked by an unauthorized person having no key.

Preferably, the guard structure of the present invention also includes a support bracket, through which the key device is mounted on the vehicle body, and wherein the guard body is provided in the support bracket. According to this structural feature, the guard body can effectively block an access from outside to the cable since an area around the support bracket, where the cable is coupled with the key device but access from outside can be made easily, can be closed by the guard body. Also, no variation occur in the mounting position of the guard body, compared with the case in which the support bracket and the guard body are arranged separately, and, accordingly, not only can the access to the cable54be effectively blocked, but also the number of component parts used can be reduced if the guard body is formed integrally with the support bracket.

In one preferred embodiment of the present invention, the key device may be fitted to a tail cover positioned proximate to the vehicle seat. According to this structural feature, if the key device is fitted to the tail cover, the spacing between the key device and the sheet locking mechanism can be reduced and the cable can have a correspondingly reduced length, making it possible to allow the guard body to facilitate blocking of the access from outside to the cable.

Where the key device is fitted to the tail cover, the guard body is preferably provided in a rear fender positioned above a rear wheel. According to this structural feature, if the guard body is provided in the rear fender, which is a relatively large component forming the vehicle body, the guard body can have so large a size as to effectively block the access from outside to the cable.

In another preferred embodiment of the present invention, the guard body may be supported by a rear frame. According to this structural feature, in the case of, for example, a motor vehicle of a type, in which the key device is disposed at a location proximate to the rear frame, even if an attempt is made to insert the tool, for example, a wire through a gap present around the key device or the cable so as to make access to the cable, this tool can be barred by the guard body and is therefore blocked from reaching the cable.

In a further preferred embodiment of the present invention, the guard body may be one of vehicle mounted component parts, in which case the guard body is supported by the rear frame through a bracket. The term “vehicle mounted component parts” is intended to mean component parts mounted on the vehicle body which include, for example, electronic control component parts, accessories, clamps, indicators or any other ancillary part. According to this structural feature, since intrusion of the tool such as a wire can be blocked merely by changing the position of the vehicle mounted component part, it is possible to effectively prevent the seat locking mechanism from being unlocked with an inexpensive simplified structure.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Hereinafter, the present invention will be described in detail in connection with preferred embodiments thereof with reference to the accompanying drawings.

Referring toFIG. 1, showing a side view of a motorcycle equipped with a seat lock guard structure according to a first preferred embodiment of the present invention, the motorcycle shown therein includes a main frame1forming a front half of a motorcycle frame structure FR, a head tube2fitted to a front portion of the main frame1, a steering shaft3rotatably inserted into the head tube2, upper and lower brackets4and5supported to the head tube2through the steering shaft3, front fork members8supported by the upper and lower brackets4and5, and a front wheel9supported rotatably by respective lower ends of the front fork members8. A handlebar10is mounted on the upper bracket4at respective upper ends of the front fork members8.

Swingarm brackets11are provided at a rear lower portion of the main frame1, and a swingarm12is pivotally supported by the swingarm brackets11through a pivot shaft13for vertical swing movement. A rear drive wheel14is rotatably carried by the swingarm12. A multi-cylinder type engine E is supported at a position below an intermediate portion of the main frame1. Also, a plurality of exhaust pipes18are fluidly connected with a cylinder head17of the engine E and are then fluidly connected with a muffler20disposed on each side of a rear portion of the motorcycle frame structure FR.

A rear frame21(seat rail assembly) rigidly coupled with a rear portion of the main frame1forms a rear half of the motorcycle frame structure FR. A rider's seat22and a fellow passenger's seat23are mounted on the rear frame21. The rear frame21includes a rear wheel fender27positioned above the rear drive wheel14. A fuel tank28is mounted on an upper portion of the main frame1, or an upper portion of the motorcycle frame structure FR and between the handlebar10and the rider's seat22. A fairing29made of a synthetic resin is fixedly mounted on a front end of the motorcycle frame structure FR to cover a front to side region of the motorcycle frame structure FR, including a front area forwardly of the handlebar10and side areas generally laterally of the motorcycle engine E,.

Except for the areas of the rear frame21, where the rider's seat22and the fellow passenger's seat23are disposed, a part of opposite lateral areas of the rear frame21is covered by a front cover24A while the remaining part of the lateral areas and a tail area of the rear frame21is covered by a rear cover24B. The front cover24A and the rear cover24B form respective parts of a tail cover24. A wheel fender flap30is connected with a rear lower portion of the rear wheel fender27so as to extend rearwardly downwardly therefrom to confront the rear wheel14, thereby covering above and rearwardly of the rear wheel14. In this condition, as shown inFIG. 2, the tail cover24is positioned in the vicinity of the rider's seat22and the fellow passenger's seat23(for example, below both the seats22and23in the illustrated instance).

Referring now toFIG. 3, showing an exploded view ofFIG. 2, the rear frame21is made of a metallic material such as an aluminum alloy and is formed in a generally rectangular frame-like shape, when viewed from top. This rear frame21is formed at its front end with a plurality of, for example, four (although only three of them are shown) connecting pieces31, through which the rear frame21is rigidly connected with the main frame1(shown inFIG. 1) by means of corresponding screw members (not shown) to extend rearwardly from the main frame1.

The rider's seat22has an engagement pawl32protruding rearwardly therefrom and engageable in a hook33defined in the rear frame21and also has a pair of mounting pieces34rigidly secured to an undersurface of a front portion of the rider's seat22for alignment with respective fitting screw holes37adefined in left and right side portion of a seat mounting area37of the rear frame21. After the engagement pawl32is engaged in the hook33in the rear frame21and the mounting pieces34are aligned with the fitting screw holes37a, fixing screws38are threaded into the fitting screw holes37athrough respective insertion holes defined in the mounting pieces34, fixing the rider's seat22to the rear frame21. In other words, the rider's seat22can be removed easily from the rear frame21merely by undoing the fixing screws38. The rear cover24B has a lower opening41that is closed by the rear wheel fender27.

The rear cover24B of the tail cover24is fixed to the rear frame21by means of threaded engagements in four fixing holes39defined in the rear cover24B, covering a rear half of the rear frame21. A top opening40of a contour conforming to the outer contour of the fellow passenger's seat23is defined in an upper portion of the rear cover24B. Thus, it will readily be seen that an utility compartment is formed below the fellow passenger's seat23, having been delimited by the rear fender27defining a bottom surface of the compartment, the rear cover24B defining side surfaces of the compartment and the top opening40defining an access opening to the compartment.

At a location rearwardly of the rider's seat22, the fellow passenger's seat23is mounted on the rear frame21so as to close the top opening40of the rear cover24B rigidly secured to the rear frame21. For this purpose, the fellow passenger's seat23is provided with an engagement pawl45rigidly connected to an undersurface of a rear portion of the seat23and, also, provided with a pair of left and right positioning studs43protruding downwardly from an undersurface of a front portion of the seat23and having an engagement projection43aprotruding downwardly from each of the positioning studs43. The fellow passenger's seat23is positioned relative to the rear frame21when the engagement pawl45is latched in a hook42of the rear frame21and the engagement projections43aare engaged in corresponding boss holes44defined in the rear frame21.

The fellow passenger's seat23is also provided with a single to-be-locked piece47having a lock hole47aengageable with a slidable lock piece74forming a part of a seat locking mechanism49as will be described in detail later, which to-be-locked piece47is positioned intermediate between the positioning studs43and43. Accordingly, when the fellow passenger's seat23is mounted on the rear frame21with the engagement pawl45latched in the hook42and also with the engagement projections43aengaged in the boss holes44as described above, the to-be-locked piece47extends through a slit-shaped insertion hole48, defined in the rear frame21, and is engaged with the slidable locking piece74. In this way, the fellow passenger's seat23is unremovably locked to the rear frame21.

A key device51for locking and unlocking the seat locking mechanism49by a key to enable the fellow passenger's seat23to be removed from the rear frame21is fixedly inserted in a key mounting hole53, defined in a front wall55of the rear cover24B, through a support bracket52. The key device52is operatively connected to the seat locking mechanism49through a cable54. The details of the seat locking mechanism49, the key device51and the cable54will now be described with particular reference toFIGS. 4 to 6.

As shown inFIG. 4, the cable54includes a cable sheath57, having a longitudinal hollow accommodating therein a tubular liner58, and a cable wire59extending through the liner58. The cable sheath57has its opposite ends each provided with a connecting member including a cap60and a clamp member61threadingly engaging the corresponding cap60, with a circumferentially extending engagement groove65defined between the clamping member61and the cap60. Opposite ends of the cable wire59protruding outwardly from the cable sheath57are provided rigidly with respective drum-shaped anchoring members62.

The key device51is in the form of a rotary lock including, as shown inFIG. 5Ain a front elevational view, a key body64having a key hole63on the front, and a key rotor67which is retained rotatably within the key body64but can be turned in response to turn of a key (not shown) inserted into the key hole63. As shown inFIG. 5Bin a rear view, a cable coupling piece68is connected with a rear surface of the key rotor67for rotation together therewith. As shown inFIG. 5C, one of the cable anchoring members62is engaged with the cable coupling piece68to connect the corresponding end of the cable54with the key device51.

Also, as shown inFIG. 5B, the key body64is formed with a mounting plate69, having two screw holes69adefined therein, so as to protrude in a direction away from the cable coupling piece68.

FIGS. 6A and 6Billustrate the seat lock mechanism49in plan and front elevational views, respectively. This seat lock mechanism49includes a mounting plate71adapted to be fixedly connected to the rear frame21, two connecting nuts72rigidly secured to the mounting plate71, a retaining piece73extending laterally outwardly from the mounting plate71with one end rigidly connected to the mounting plate71, and a locking piece74slidably retained in a slide guide groove71adefined in the mounting plate71. One of opposite ends, i.e., a right end, of the locking piece74protruding outwardly from the mounting plate71is rendered to be a locking portion74ahaving an inclined guide surface. The other of the opposite ends of the locking piece74is bent at right angles to define a retaining portion74bhaving a cable wire mounting groove74copening upwardly. One of the cable anchoring members62of the cable54is coupled with the retaining portion74bwith the cable wire59passed through the cable wire mounting groove74c.

On the other hand, the other end of the retaining piece73remote from the mounting plate71is bent at right angles to extend substantially parallel to the retaining portion74bof the locking piece74, defining a retaining portion73a. The retaining portion73ahas a cable sheath mounting groove73bopening upwardly. One of the cable caps60of the cable54is coupled with the retaining piece73with the groove65of the cable54engaged in the corresponding cable sheath mounting groove73b.

Referring toFIG. 6B, when the cable wire59is pulled by turn of a key inserted into the key device51, the locking piece74is moved from a seat locked position shown by a solid line, in which the locking portion74aof the locking piece74is engaged in the lock hole47ain the to-be-locked piece47, towards a seat unlocked position shown by the phantom line, in which the locking portion74ais disengaged out of the lock hole47a. In this unlocked position, the fellow passenger's seat23(FIG. 3) is unlocked. With the fellow passenger's seat23unlocked, the fellow passenger's seat23can be removed from the motorcycle rear frame21.

Referring toFIG. 7, the support bracket52for supporting the key device51is made of a metallic material and is formed integrally with a body plate77having a key mounting hole77a, a lightening hole77band a pair of mounting holes77call formed therein, a support piece78formed by bending one side portion of the body plate77at predetermined angles relative to the remaining portion of the body plate77and used to support the cable54, two mounting pieces79and80formed by bending upper and lower end portions of the body plate77at right angles relative to the remaining portion of the body plate77, and a guard piece81protruding laterally from the lower mounting piece80in a direction conforming to the support piece78. The guard piece81forms a guard body of the present invention.

The support piece78is formed with a mounting groove78afor engagement with the corresponding groove65of the cable54shown inFIG. 4. The guard piece81is made up of a retaining piece81a, protruding from the lower mounting piece80, and a guard portion81bextending substantially vertically from the retaining piece81a. The upper and lower mounting pieces79and80are formed with one mounting hole79aand two mounting holes80a, respectively.

Hereinafter, the manner of mounting the support bracket52(FIG. 7), the key device51(FIGS. 5A to 5C) and the seat locking mechanism49(FIGS. 6A and 6B) will be described in detail. In the first place, one end of the cable54is connected to the support bracket52and the key device51. More specifically, one end of the cable wire59of the cable54is connected to the cable coupling piece68of the key device51in the manner described with reference toFIGS. 5A to 5C. One end of the cable sheath57of the cable54is passed through and fixed in the mounting groove78aof the support piece78in the support bracket52shown inFIG. 7.

After, as shown by the arrow inFIG. 3, the key body64of the key device51is passed through the key mounting hole77ain the support bracket52, fixing screws93are then passed respectively through the two mounting holes77c(FIG. 7) in the support bracket52and are then threaded into the associated screw holes69ain the key device51to connect the key device51to the support bracket52.

Thereafter, the key body64protruding forwardly from the key mounting hole77ain the support bracket52is passed through the key mounting hole53in the rear cover24B from inside of the rear cover24B and, while the body plate77of the support bracket52is held in abutment with an inner surface of the front wall55of the rear cover24B, fixing screws82are, after the mounting holes79aand80ain the mounting pieces79and80of the support bracket52shown inFIG. 7have been aligned with respective fixing nut portions91and92protruding outwardly from the front wall55of the rear cover24B, threaded into the fixing nuts91and92through the mounting holes79aand80a. By so doing, the support bracket52is fixed to the inner surface of the front wall55of the rear cover24B. A fixing ring83(FIG. 3) is mounted on a free end of the key body64, which protrudes outwardly from the key mounting hole53in the rear cover24B, to improve the outer appearance.

Prior to the mounting of the seat locking mechanism49, the retaining piece73of the seat locking mechanism49is connected to the opposite end of the cable sheath57through the corresponding cable cap60while the locking piece74is connected to the opposite end of the cable wire59in the manner described with particular reference toFIGS. 6A and 6B. On the other hand, as shown inFIG. 3, a bridge portion84provided in the rear half of the rear frame21is formed, in addition to the boss holes44and the slit-shaped insertion hole48, with a pair of insertion holes87. After the opposite end of the cable54has been connected to the seat locking mechanism49, the seat locking mechanism49is fixed to the bridge portion84of the rear frame21by holding the mounting plate71of the seat locking mechanism49in abutment with an undersurface of the bridge portion84, aligning the connecting nuts72with the respective insertion holes87of the bridge portion84and screwing fixing screws88into the connecting nuts72through the insertion holes87.

When the fellow passenger's seat23is mounted onto the rear frame21, the free end of the to-be-locked piece47of the seat23, then moving downwardly in a direction towards the rear frame21, slides along the inclined guide surface of the locking portion74aof the locking piece74while urging the locking piece74to move a stroke S backwardly to a position shown by the phantom line inFIG. 6A. Once the locking piece74is so moved backwardly, the locking piece74is, by the action of a pushing force exerted by the cable wire59of the cable54, driven in a direction counter to the direction of backward movement until the locking portion74aof the locking piece74is inserted into and then engaged in the locking hole47ain the to-be-locked piece47to establish the seat locked position, in which the fellow passenger's seat23is locked to the rear frame21.

On the other hand, when the fellow passenger's seat23is desired to be released, a key has to be inserted into the key hole63of the key device51and then turned. When the key is turned, the key rotor67of the key device51is turned from a seat lock position K1, shown inFIG. 5B, to a lock release position K2, accompanied by a corresponding turn of the cable coupling piece68about the longitudinal axis of the key rotor67. Once the cable coupling piece68is so turned, the cable wire59of the cable54is pulled, accompanied by movement of the slidable lock piece74of the seat locking mechanism49to a lock release position shown by the phantom line inFIG. 6Bto thereby allow the fellow passenger's seat23to be unlocked.

As shown inFIGS. 8 and 9, the rear fender27positioned beneath the rear cover24B is formed integrally with a first guard plate89, employed as an additional guard body and positioned rearwardly of the guard piece81of the support bracket52forming a part of the key device51, and a second guard plate90employed as an additional guard body and positioned rearwardly of the first guard plate89and forwardly of the cable54. Each of the guard plates89and90is in the form of an upright wall rising from the rear fender27. The first guard plate89blocks a tool that is inserted through a gap85delimited between the body plate77and the guard portion81bof the support bracket52shown inFIG. 7, to thereby prevent the tool from being further advanced. On the other hand, the second guard plate90blocks a tool that is inserted towards the guard piece81from front and then advanced beneath or laterally of the guard piece81towards the inside of the rear cover24B, to thereby prevent the tool from being further advanced.

It is, however, to be noted that in the practice of the present invention, one or both of the first and second guard plates89and90may be dispensed with.

When the rider's seat22shown inFIG. 2is removed, a portion of the rear cover24B, where the rider's seat22is mounted, is opened as shown inFIG. 8, with an opening96exposed to the outside. In this condition, a large gap exists between a lower portion of the rear cover24B and the rear fender27. Even if an attempt is made to unlock the fellow passenger's seat23by inserting an elongated flexible tool such as a wire into a space in the lower portion of the rear cover24B through the opening96until the tip of the tool hitches the cable54and then by pulling the inserted tool together with the cable54, the tool can be brought into contact with the upright guard portion81bof the guard piece81in the support bracket52, thereby preventing the elongated tool from reaching the cable54.

According to the foregoing embodiment, an access from the outside of the vehicle body to the cable54can be effectively barred since the guard piece81serves to block an easy-to-access area adjacent the support bracket52, where the cable54is arranged to be coupled with the key device51. Also, since the guard piece81is formed integrally with the support bracket52, no variation occur in the mounting position of the guard piece81, compared with the case in which the support bracket52and the guard piece81are arranged separately, and, accordingly, not only can the access to the cable54be effectively avoided, but also the number of component parts used can be reduced. Also, even though the tool is inserted from anywhere and any direction, the access of the tool to the cable54can be effectively prevented by the presence of the first and second guard plates89and90provided in the rear fender27.

Considering that the key device51is fixedly fitted to the front wall of the rear cover24B of the tail cover24and substantially intermediate of the width of the vehicle body, the cable54extending between the key device51and the seat locking mechanism49, both shown inFIG. 9, can have a reduced length and, consequently, even if the number of the guard plates89and90that are provided in the rear fender27can be reduced, the access of the tool to the cable54can be barred with a simplified construction. In the illustrated instance, the cable54is accommodated within an interior space defined by the rear fender27, the rear cover24B of the tail cover24and the fellow passenger's seat23.

It is to be noted that one of the guard piece81and the guard plates89and90may be dispensed with and, where the guard piece81is not employed, the first guard plate89is preferably arranged in the vicinity of the opening96.

FIGS. 10 to 12illustrate a second preferred embodiment of the present invention. In particular,FIG. 10illustrates a fragmentary side view showing a rear portion of the vehicle body equipped with the guard structure for the seat lock. The motorcycle shown therein makes use of a unitary seat structure94, in which the rider's seat and the fellow passenger's seat are formed integrally with each other.

The unitary seat structure94is generally elongated in a longitudinal direction of the vehicle body and, therefore, the use is made of a double lock device including, as shown inFig. 11, a front seat locking mechanism97and a rear seat locking mechanism98to lock the unitary seat structure94. The front seat locking mechanism97is of a twin type, in which projections of a slider95slidable in a direction transverse of the front seat locking mechanism97can be engaged in respective recesses defined in corresponding two lock pins103fixed in downward orientation to the unitary seat structure94(FIG. 10).

On the other hand, the rear seat locking mechanism98is of a type substantially identical with the seat locking mechanism49shown inFIG. 3and employed in the practice of the first embodiment of the present invention and is used to lock the unitary seat structure94when a slider106movable in the longitudinal direction of the vehicle body is engaged in a lock hole105defined in a to-be-locked piece104fixed in downward orientation to the seat structure94.

The front and rear seat locking mechanism97and98are operated through respective cables100and101by inserting a key into the sole key device99. For this purpose, the key device99is arranged at a location generally intermediate between the front and rear locking mechanisms97and98and rigidly secured to the rear fender108. More specifically, the key device99is fixed to the rear fender108by aligning two fixing holes109of the key device99with respective boss holes (not shown) defined in bosses110of the rear fender108and then by screwing corresponding tapping screws (not shown) into those boss holes. A key hole (not shown) of the sole key device99is so oriented downwardly that the presence of the key hole cannot be recognized by any person other than the rider of the motorcycle. Therefore, a key130can be inserted into the key hole from below in a direction, shown by the arrow-headed broken line.

The rear frame107includes an upper frame member107aand a lower frame member107bpositioned one above the other. The rear fender108is fixed to the rear frame107by means of screws. A tail cover102is fixed to the upper frame member107aof the rear frame107by means of bolts threaded into respective rubber nuts (not shown) which are plugged in four boss holes111ain four corresponding bosses111provided in the rear frame107. This tail cover102is of a shape turned backwards at a lower portion thereof so that the key device99, the cables100and101and the neighborhood of the key device99can be concealed, and an opening112is defined at front end thereof. For this reason, a tool such as a wire can be inserted from outside of the vehicle body through the opening112.

In view of the above, in order to avoid an insertion of the tool, a bracket113supporting the two cables100and101is arranged forwardly of and close to the key device99, and a lamp relay114for actuating direction indicating blinkers one at a time is fixedly mounted on this bracket113. Accordingly, the lamp relay114, which is one of vehicle mounted component parts, is utilized to serve as a guard body for blocking an access to the cables100and101from outside.

As shown inFIG. 12, the bracket113is prepared from a sheet metal by the use of any known press work and is formed integrally with a fixing piece117to be secured to the rear frame107, a support piece118for supporting the cables100and101and a mounting piece119on which the lamp relay114is mounted. The support piece118has a pair of support grooves118aand118bof a substantially U-shaped configuration opening rearwardly, in which grooves118aand118bthe cables100and101are engaged, respectively. The fixing piece117has an upper end that is bent to extend inwardly to define a detent pawl117a. The mounting piece119includes a pair of engagement pawls119aprotruding from opposite sides of an upper end of the mounting piece119and a bent portion120at a lower end thereof. The mounting piece119protrudes slightly laterally of the upper frame member107athrough the bent portion120.

On the other hand, the lamp relay114includes a relay body inserted into a protective casing121made of a rubber material, which casing121is formed at its inner side with a slit122for insertion of the mounting piece119of the bracket113. Accordingly, the protective casing121is supported by the mounting piece119while seated on the bent portion120, when the mounting piece119is inserted into the slit122with the engagement pawls119aengaged non-detachably with an upper edge portion of the slit122. The bracket113is secured to the upper frame member107awhen, after the detent pawl117aof the fixing piece117has been brought into abutment with an upper surface of the upper frame member107ato prevent the bracket113from rotating and a fixing hole123defined in the fixing piece117has been aligned with a mounting hole (not shown) defined in the upper frame member107aof the rear frame107, a set screw (not shown) is threaded into a pop-nut (also not shown) inserted in the mounting hole of the upper frame member107a.

In this guard structure described above, when an attempt is made to insert the tool such as a wire is inserted through the opening112in the tail cover102towards the cables100and101as shown by the arrow-headed solid line P inFIG. 11, the tool is blocked by the lamp relay114and, hence, cannot reach the cables100and101. Also, even when the cables100and101are pulled forwards (outwardly) by the tool in a direction shown by the arrow Q inFIG. 12, further forward pull of the cables100and101can be blocked by the support piece118. Moreover, with this guard structure, merely by changing the position of the lamp relay114, intrusion of the tool can be prevented by the lamp relay114to avoid an unnecessary unlocking with an inexpensive simplified structure.

It is to be noted that in place of the lamp relay114used as the guard body, a guard piece similar to the guard piece81shown inFIG. 7and described in connection with the first embodiment may be formed integrally with or rigidly connected with the bracket113.

It is also to be noted that the support bracket52shown inFIG. 7and described in connection with the first embodiment and the bracket113shown inFIG. 12and described in connection with the second embodiment may not be made of a metallic material as described, but may be made of a synthetic resin.

Although the present invention has been fully described in connection with the preferred embodiments thereof with reference to the accompanying drawings which are used only for the purpose of illustration, those skilled in the art will readily conceive numerous changes and modifications within the framework of obviousness upon the reading of the specification herein presented of the present invention. By way of example, the guard structure for the seat lock according to the present invention, although having been shown and described as applied to the motorcycle, can be equally applied to, for example, a three-wheeled motor vehicle or a four-wheeled off-road motor vehicle.

Accordingly, such changes and modifications are, unless they depart from the scope of the present invention as delivered from the claims annexed hereto, to be construed as included therein.