Abstract:
A collapsible upright wall extends the height of the sides on the load hauling box on a truck. The collapsible upright wall comprises a fabric which when vertically stretched provides adequate resistance to substantial lateral load. A method of increasing the volumetric capacity of the box on a truck comprises the steps of: a) providing a rectangular frame above, and dimensioned to seat adjacent to an open top side portion of the load hauling box on the truck; b) providing a substantial lift mechanism to uniformly lift the rectangular frame above the box; and, c) providing and attaching an elongate strip of fabric having a top elongate side portion peripherally attached to the rectangular frame, and a bottom elongate side portion peripherally attached to the open top side portion of the box. Then when the rectangular frame is lifted to an upper operable position the fabric is stretched taut and is thereby able to sustain significant lateral load.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to a hydraulic shock absorber.  
           [0003]    2. Description of the Related Art  
           [0004]    A hydraulic shock absorber is provided with an axle side mounting portion in a lower portion of a damper tube, and with a vehicle body side mounting portion in a damper rod. The hydraulic shock absorber absorbs an impact applied from a road surface by a suspension spring interposed between the damper tube and the damper rod, and damps the expansion and compression vibration of a suspension spring by a damping apparatus installed in the damper tube.  
           [0005]    In a conventional hydraulic shock absorber, the vehicle body side mounting portion is held by a mount rubber supported to the damper rod. The mount rubber is supported by a mount support collar provided in the damper rod to be mounted to the damper rod. A fixing configuration of the mount support collar to the damper rod is a configuration described in Japanese Utility Model Publication No. 61-12439 (patent document 1). In this configuration, an outer diameter of a mounting portion in the damper rod is smaller than an outer diameter of a lower portion side with respect to the mounting portion. The mount support collar is mounted on a large diameter step portion provided in a lower portion of a small diameter mounting portion which is held.  
           [0006]    Further, another fixing configuration of the mount support collar to the damper rod is also a configuration described in patent document 1. In this configuration, a C-ring is engaged with a groove provided in an outer periphery of the damper rod, and the mount support collar is mounted on the C-ring which is held.  
           [0007]    However, in the configuration in which the mount support collar is mounted on the step portion provided in the damper rod which is held, the mounting portion in an upper side of the step portion in the damper rod is made small in diameter, whereby strength of the damper rod is lowered. For example, in the case that a 1 mm step portion is formed in a damper rod having an outer diameter 12.5 mm, the diameter of the damper mounting portion is 10 mm, and strength thereof is lowered.  
           [0008]    In the configuration in which the mount support collar is mounted on the C-ring engaged with the groove provided in the damper rod which is held, the depth of the groove is sufficiently set at approximately 0.5 to 0.75 mm. In the damper rod having an outer diameter 12.5 mm, the groove diameter is about 11 mm, so that the strength of the damper rod is not substantially lowered. In this case, however, the strength of the C-ring holding the mount support collar against an axial load of the damper rod is law, and two parts comprising the C-ring and the collar are required, so that assembling work is increased.  
         SUMMARY OF THE INVENTION  
         [0009]    An object of the present invention is to securely fix a mount support collar to a damper rod against an axial load of the damper rod without reducing the strength of the damper rod, while reducing an assembling work involved in assembling the mount support collar to the damper rod.  
           [0010]    The present invention provides a hydraulic shock absorber in which a mount support collar is fixed to a damper rod, configured such that a collar fixing groove is provided in an outer periphery of the damper rod, and the mount support collar is fixed to the collar fixing groove via a caulking. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]    The present invention will be more fully understood from the detailed description given below and from the accompanying drawings, which should not be taken to be a limitation on the invention, but are for explanation and understanding only.  
         [0012]    The drawings:  
         [0013]    [0013]FIG. 1 is a half cross sectional view showing a hydraulic shock absorber;  
         [0014]    [0014]FIG. 2 is a cross sectional view showing a mounting arrangement of a mount to a damper rod;  
         [0015]    [0015]FIG. 3 is a front elevational view showing the damper rod;  
         [0016]    [0016]FIG. 4 is a cross sectional view showing a mount support collar; and  
         [0017]    [0017]FIG. 5 is a half cross sectional view showing a caulking arrangement between the mount support collar and a rebound seat. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0018]    As shown in FIG. 1, a hydraulic shock absorber  10  is configured such that a cylinder  12  is built in a damper tube  11  to form a double tube. A damper rod  13  is inserted to the cylinder  12 . An axle side mounting portion  14  constituted by an i-joint is provided in a lower portion of the damper tube  11 , and a vehicle body side mounting portion  15  is provided in an upper portion of the damper rod  13 , whereby the suspension apparatus of a vehicle is configured.  
         [0019]    In the hydraulic shock absorber  10 , a suspension spring  17  is interposed between a lower spring seat  16  in an outer periphery of the damper tube  11  and an upper spring seat (not shown) provided in the vehicle body side mounting portion  15  in an upper end portion of the damper rod  13 .  
         [0020]    In the hydraulic shock absorber  10 , a rod guide  21  for the damper rod  13  inserted to the cylinder  12 , a bush  22  and an oil seal  23  are fixed to be clamped between an upper end caulked portion  24  of the damper tube  11  and an upper end of the cylinder  12 .  
         [0021]    The hydraulic shock absorber  10  has a piston valve apparatus  30  and a bottom valve apparatus  40 . The hydraulic shock absorber  10  damps the expansion and compression vibration of the damper rod  13  caused by an absorption of the impact force by the suspension spring  17 , on the basis of a damping force generated by the piston valve apparatus  30  and the bottom valve apparatus  40 .  
         [0022]    Piston Valve Apparatus  30 :  
         [0023]    The piston valve apparatus  30  is configured such that a valve stopper  31 , a check valve  32 , a piston  33 , a disc valve  34  and a valve stopper  35  are attached to a damper rod  13 , and are fixed by a piston lock nut  36 .  
         [0024]    During compression, oil in a piston side oil chamber  37 A passes through a compression side flow passage  38 A of the piston  33 , flexibly deforms the check valve  32  to open, and is introduced to a rod side oil chamber  37 B. During expansion, oil in a rod side oil chamber  37 B passes through an expansion side flow passage  38 B (not shown) of the piston  33 , flexibly deforms the disc valve  34  to open, is introduced to the piston side oil chamber  37 A, and generates an expansion side damping force.  
         [0025]    Bottom Valve Apparatus  40 :  
         [0026]    In the hydraulic shock absorber  10 , a gap between the damper tube  11  and the cylinder  12  is formed as a reservoir chamber  41 , and an inner portion of the reservoir chamber  41  is sectioned into an oil chamber and a gas chamber. Further, in the bottom valve apparatus  40 , a bottom portion  11 A of the damper tube  11  is closed by a spinning operation. A bottom piece  43  separating the piston side oil chamber  37 A in an inner portion of the cylinder  12  from the reservoir chamber  41  is arranged in a lower end portion of the cylinder  12 . The piston side oil chamber  37 A and the reservoir chamber  41  may be in fluid communication via a flow passage (not shown) provided in the bottom piece  43 . A bolt  44  and a nut  45  are fastened to the bottom piece  43 , and a disc valve  46 , the bottom piece  43 , a check valve  47  and a valve stopper  48  are interposed between the bolt  44  and the nut  45 .  
         [0027]    During compression, oil at an amount corresponding to a forward moving volume of the damper rod  13  moving forward to the cylinder  12  passes through a compression side flow passage  49 A of the bottom piece  43  from the piston side oil chamber  37 A, flexibly deforms the disc valve  46  to open, is pushed out to the reservoir chamber  41 , and obtains a compression side damping force. During expansion, oil in an amount corresponding to a backward moving volume of the damper rod  13  moving backward from the cylinder  12  pushes open the check valve  47 , and is re-supplied from the reservoir chamber  41  to the piston side oil chamber  37 A via an expansion side flow passage  49 B (not shown) of the bottom piece  43 .  
         [0028]    In the hydraulic shock absorber  10 , a rebound spring  53 , which is compression deformed when the damper rod  13  is fully expanded in the most expanded state of the hydraulic shock absorber  10 , is interposed between a first collar  51  and a second collar  52 . Around the damper rod  13  positioned in the rod side oil chamber  37 B of the cylinder  12 , the first collar  51  is fixed to a side of the piston  33  (a lower side of the damper rod  13 ), and a second collar  52  is loosely fitted to a side of the rod guide  21  (an upper side of the damper rod  13 ). A rebound seat  50  is fixed to an outer periphery of a portion inserted to the cylinder  12  in the damper rod  13  in the manner mentioned below, and the first collar  51  loaded in a lower end portion of the rebound spring  53  is mounted on the rebound seat  50  to be supported.  
         [0029]    In the hydraulic shock absorber  10 , a mounting configuration of the vehicle body side mounting portion  15  to the upper portion of the damper rod  13  is configured as follows (FIG. 2). A mount support collar  60  is fixed to an outer periphery protruding from the cylinder  12  of the damper rod  13  in the manner mentioned below. A receiving seat  61 , a joint collar  62 , and a receiving seat  63  which are inserted to a mount mounting portion  77 , mentioned below, of the damper rod  13  are mounted in this order and supported on the mount support collar  60 . Mount rubbers  64 A and  64 B are provided between the receiving seat  61  and the receiving seat  63 , and a mount fixing nut  65  is screwed into an upper end portion of the damper rod  13 , thereby clamping the base end portion  15 A of the vehicle body side mounting portion  15  between the mount rubbers  64 A and  64 B.  
         [0030]    Accordingly, the rebound seat  50  and the mount support collar  60  mentioned above are fixed to the damper rod  13  in the following manner.  
         [0031]    In the damper rod  13 , as shown in FIG. 3, a lower end portion having a length L1 is formed as a small-diameter piston mounting portion  71  (for example, having a diameter 8 mm), and a screw portion  71 A (for example, M8) for the piston fixing nut  36  is provided in a leading end portion of the piston mounting portion  71 . The damper rod  13  is provided with a lower shaft portion  72  (for example, having a diameter 12.5 mm) having a length L2 on the piston mounting portion  71  and may be continuously arranged via a step portion. The damper rod  13  may be provided with a seat fixing groove  73  (for example, having a groove diameter 11.5 mm) on the lower shaft portion  72 , may be provided with an intermediate shaft portion  74  (for example, having a diameter 12.5 mm) having a length L3 on the seat fixing groove  73 , may be provided with a collar fixing groove  75  (for example, having a groove diameter 11 mm) on the intermediate shaft portion  74 , and may be provided with an upper shaft portion  76  (for example, having a diameter 12.5 mm) having a length L4 on the collar fixing groove  75 . The damper rod  13  may be provided with a mount mounting portion  77  (for example, having a diameter 12 mm) having the same diameter as that of the upper shaft portion  76  and a length L5 on the upper shaft portion  76 , and may be provided with a screw portion  77 A (for example, M12) for the mount fixing nut  65  in a leading end portion of the mount mounting portion  77 .  
         [0032]    The rebound seat  50  and the mount support collar  60  are formed in an identical flanged circular tube shape as shown in FIG. 4.  
         [0033]    The rebound seat  50  is configured, as shown in FIG. 5, such that a circular tube portion  50 A is fixed to the seat fixing groove  73  of the damper rod  13  by caulking. The first collar  51  for the rebound spring  53  is mounted on an upper end surface of a flange portion  50 B to be supported. The seat fixing groove  73  can be in the form of a triangular groove, a trapezoidal groove or the like. The circular tube portion  50 A of the rebound seat  50  may be caulked in an entire periphery or may be partly caulked in a plurality of positions such as four or eight positions in a peripheral direction.  
         [0034]    In the mount support collar  60 , as shown in FIG. 5, a circular tube portion  60 A is fixed to the collar fixing groove  75  of the damper rod  13  by a caulking operation. The receiving seat  61  for the mount rubbers  64 A and  64 B of the vehicle body side mounting portion  15  is mounted on the upper end surface of the flange portion  60 B to be supported. The collar fixing groove  75  can be in the form of a triangular groove, a trapezoidal groove or the like. The circular tube portion  60 A of the mount support seat  60  may be caulked along an entire periphery or may be partly caulked in a plurality of positions such as four or eight positions in a peripheral direction.  
         [0035]    The circular tube portion  60 A of the mount support collar  60  is fixed to the collar fixing groove  75  of the damper rod  13  by a caulking operation, and is attached to the upper shaft portion  76 . Accordingly, in the damper rod  13 , outer diameters of upper and lower portions (the intermediate shaft portion  74  and the upper shaft portion  76 ) clamping the collar fixing groove  75  in an axial direction are set to the same diameter (for example, the diameter 12.5 mm. The upper portion of the collar fixing groove  75  and the upper shaft portion  76  in the damper rod  13  are set to a mounting portion  77 , and a threaded portion for the mount fixing nut  65  is provided in an upper end portion of the mounting portion  77 .  
         [0036]    An assembling procedure of the hydraulic shock absorber  10  is as follows.  
         [0037]    (1) The piston  33 , the rebound seat  50  and the like are provided from the lower portion to the intermediate portion of the damper rod  13 , and the rebound spring  53  and the like are loaded and inserted to the cylinder  12 .  
         [0038]    (2) The rod guide  21 , the oil seal  23  and the like are assembled in the upper portion of the damper tube  11  and the cylinder  12 , whereby the upper end caulked portion  24  of the damper tube  11  is provided.  
         [0039]    (3) The mount support collar  60  and the like are assembled in the upper portion of the damper rod  13 , whereby the vehicle body side mounting portion  15  is provided.  
         [0040]    In accordance with the present embodiment, the following operational advantages can be obtained.  
         [0041]    (1) A depth of the collar fixing groove  75  required for caulking the mount support collar  60  is set to approximately 0.5 to 0.75 mm, and in the damper rod having the outer diameter 12.5 mm, the groove diameter is approximately 11 mm and not to be minimized, so that the strength of the damper rod  13  is not reduced.  
         [0042]    (2) Since the mount support collar  60  is fixed to the collar fixing groove  75  by caulking, it is possible to firmly and securely fix the mount support collar  60  against the axial load of the damper rod  13 , with the result such that reliability is improved.  
         [0043]    (3) Since the mount support collar  60  is directly assembled in the damper rod  13 , the number of parts is not increased and assembling work can be reduced.  
         [0044]    (4) When conveying the mount support collar  60  in a sub-assembly state in which the mount support collar  60  is assembled to the damper rod  13 , it does not require any special precautions to prevent the mount support collar  60  from coming off.  
         [0045]    (5) Since the outer diameters of the upper and lower portions (the intermediate shaft portion  74  and the upper shaft portion  76 ) clamping the collar fixing groove  75  of the damper rod  13  are set to the same diameter (for example, 12.5 mm), it is not necessary to arrange the collar fixing groove  75  and the mount mounting portion  77  in the upper portion of the upper shaft portion  76  to be minimized in diameter and arranged in a stepped shape. Even in the case that the outer diameter of the damper rod  13  is small and the step portion for mounting the mount support collar  60  can not be formed, it is possible to securely fix the mount support collar  60 . Although the present invention is particularly advantageous for the small-diameter damper rod  13 , this invention can be applied without being limited to the damper rod  13  having a small diameter. When the outer diameter of the damper rod  13  is close to the thread diameter of the mounting fixing nut  65  (for example, when the mounting fixing nut  65  of M12 mm is employed with respect to the damper rod  13  having an outer diameter 12.5 mm), the step portion is not provided in the damper rod  13 . This arrangement is particularly advantageous.  
         [0046]    (6) The parts can be used interchangeably and the cost can be reduced by forming the mount support collar  60  and the rebound seat  50  in an identical shape. At this time, it is possible to use a caulking machine of the rebound seat  50  interchangeably with a caulking machine of the mount support collar  60 , and it is thereby possible to simplify the equipment.  
         [0047]    As heretofore explained, embodiments of the present invention have been described in detail with reference to the drawings. However, the specific configurations of the present invention are not limited to the illustrated embodiments but those having a modification of the design within the range of the present claimed invention are also included in the present invention. For example, the hydraulic shock absorber according to the present invention can be applied to a front damper without being limited to the rear damper of the vehicle.  
         [0048]    According to the present invention, it is possible to securely fix the mount support collar to the damper rod against the axial load of the damper rod without reducing the strength of the damper rod while reducing the assembling work, during assembly of the mount support collar to the damper rod.  
         [0049]    Although the invention has been illustrated and described with respect to several exemplary embodiments thereof, it should be understood by those skilled in the art that the foregoing and various other changes, omissions and additions may be made to the present invention without departing from the spirit and scope thereof. Therefore, the present invention should not be understood as limited to the specific embodiment set out above, but should be understood to include all possible embodiments which can be encompassed within a scope of equivalents thereof with respect to the features set out in the appended claims.