JP3965447B2 - Backhoe - Google Patents

Description

  The present invention relates to an improvement in a cover opening / closing mechanism for viewing the inside of a backhoe.

  A backhoe having a structure in which a battery is disposed in a main frame of the backhoe and a bonnet pivots up and down on the main body frame is known, and the applicant further covers a cover that covers the upper portion of the battery. Japanese Patent Application No. Hei 6-296488 has already filed a configuration that can be opened and closed by turning up and down.

JP 61-218426 A

Among the conventional backhoes as described above, the battery cover with the conventional up-and-down rotating structure is opened because the bonnet closes without trouble even when the upper part of the battery is opened by rotating upward. It turns out that there is a risk of closing the hood. If the cover is left open, engine waste heat from the main body frame may enter the suction side of the engine radiator in the bonnet again and cause overheating of the engine.

The present invention uses the following means in order to solve the above problems.
A battery (BT) is disposed in the main frame (2) of the backhoe, and is opened and closed by rotating up and down on the main frame (2), and a bonnet (3) for housing the engine (E) is attached inside. In the configuration, the bonnet (3) has a pin (38) which is a horizontal rotation shaft at the front upper end, and is configured to be able to be opened by rotating the rear part of the bonnet (3) upward. (3) A battery cover (41) that enables maintenance of the engine (E) housed in the battery (BT) and the battery (BT) disposed in the main body frame (2) and covers the upper part of the battery (BT). Is configured to open and close by rotating in the horizontal direction around a vertical rotation shaft (42) disposed on the main body frame (2), and when the battery cover (41) is opened, the battery Cover (41) Even if the bonnet 3 is rotated downward to bring the bonnet (3) into a closed state with the battery cover (41) opened and protruding outward from the main body frame (2), the main body frame (2) A battery cover (41) is interposed between the bonnet (3) and cannot be closed .

Since the present invention is configured as described above, the following effects can be obtained.
When opening the cover of the battery installed in the body frame, when you try to close the bonnet by turning it downward, the opened cover protrudes outward, so you can see that you forgot to close the cover. Also, since the cover is interposed between the main body frame and the bonnet, the bonnet is not closed.
If you forget to close the cover on the top of the battery, the exhaust from the radiator of the engine will circulate again from the opened battery cover to the suction side of the radiator, and the waste heat from the body frame will be lost. Overheating of the engine due to re-flowing into the room bonnet is avoided.

  Embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is an overall side view of a backhoe according to the present invention, FIG. 2 is a hydraulic circuit diagram for driving for driving that enables two-speed shifting, and FIG. 3 is a front view showing a connection configuration between a backhoe operating pedal 12 and a front column CV. 4 is a partially enlarged front view of FIG. 3, FIG. 5 is a hydraulic circuit diagram in which the traveling drive hydraulic circuit shown in FIG. 2 is applied to the control valve CV of the backhoe, and FIG. 6 is a second speed in the hydraulic circuit shown in FIG. FIG. 7 is a hydraulic circuit diagram at the time of PTO driving in the hydraulic circuit shown in FIG.

  8 is a side view of a working arm portion of a backhoe in which a hydraulic takeout hose PH is piped inside the boom, FIG. 9 is a view taken along the line XX in FIG. 8, and FIG. 11 is a partial side view, FIG. 11 is a partial side view, FIG. 12 is an internal side view showing the piping configuration of the hydraulic outlet hose and cylinder hose at the boom base end, FIG. 13 is an internal plan view, and FIG. FIG. 15 is a front sectional view, FIG. 16 is an internal side view showing the piping configuration of the hydraulic take-out hose and the cylinder hose at the bent part of the boom, FIG. Is an internal plan view showing the arrangement structure of the clamp member B in the bent part of the boom, FIG. 18 is an internal front view, FIG. 19 is a perspective view of the rubber clamp 33, and FIG. .

  21 is a side view of the backhoe main body, FIG. 22 is also a plan view, FIG. 23 is a rear view of the front column 5 showing the arrangement structure of the starter switch SS, and FIG. 24 is a view taken along arrow YY in FIG. 25 is an internal side view of the front column 5, FIG. 26 is a side view of a backhoe main body showing the arrangement of a conventional starter switch, and FIG. 27 is a view taken along arrow YY in FIG.

  28 is a side view of the backhoe body showing the opening / closing structure of the bonnet 3, FIG. 29 is also a rear view, FIG. 30 is a partial front sectional view showing the mounting structure of the seat 4 to the bonnet 3, and FIG. FIG. 32 is a plan view of the backhoe main body showing the opening / closing structure of the battery cover 41.

  FIG. 33 is a hydraulic circuit diagram at the first speed stage of a hydraulic circuit configured to extract a pilot pressure for two-speed shifting from a return oil circuit common to the conventional control valve CV, and FIG. 34 is a hydraulic circuit diagram at the second speed stage. is there.

  Next, an improved configuration of the seat and the battery cover related to the opening / closing structure by the vertical rotation of the bonnet 3 according to the present invention will be described. As shown in FIGS. 28 and 29, the bonnet 3 has a pivot shaft at the front upper end, and is pivoted upward as indicated by 3 'in the figure, and is stored in the bonnet 3. Maintenance of the engine E and the battery BT disposed in the main body frame 2 is enabled. Further, when the hood 3 is opened, the seat 4 is integrated with the bonnet 3 as shown by 4 'in FIG. 28. However, the seat 4 is not wet when it rains. In order to achieve this, it is possible to rotate forward independently.

  In this description, a structure for fixing the seat 4 to the bonnet 3 will be described. Conventionally, as shown in FIG. 31, a bracket 36 bent in a U-shape when viewed from the front is fixed on the upper surface of the bonnet 3, while a bracket 37 bent in an L-shape when viewed from the left and right is provided on the lower surface of the seat 4. 37 were fixed, and these were fixed in a skewered manner with a round bar-shaped pin 38 as shown in FIG.

  In this structure, there is a problem that the pin 38 can freely rotate to some extent within the pin hole formed in the brackets 36 and 37. That is, the seat 4 rotates with respect to the bonnet 3 using the pin 38 as a rotation fulcrum. For example, as described above, the ability to rotate is convenient when the seat 4 is rotated forward so that the seating surface of the seat 4 does not get wet when it rains. Thus, for example, when the seat 4 is tilted forward in the case of rain, if the backhoe is tilted with the rear side down, the seat 4 that has been tilted forward will fall back to the original position. There is a problem that it will return to. Further, when the bonnet 3 is rotated upward and opened, the seat 4 is pushed up from below, so that the bonnet 3 is rotated integrally. However, when the opened bonnet 3 is rotated downward and closed, the pin 38 is rotated. Due to the movement, the seat 4 does not rotate integrally with the bonnet 3, and the rotation of the bonnet 3 is delayed. And when the bonnet 3 is completely closed, the seat 4 suddenly returns to its original position.

  Therefore, in the embodiment shown in FIG. 30, the friction force is applied between the pin 38 and the brackets 36 and 37. First, the pin 38 is normally inserted into the pin hole of the bracket 37 on one side and the bracket 36 on the same side, and the pin is inserted between the pin hole of the other side bracket 37 and the bracket 36 on that side. A disc spring 39 is provided around 38, and a disc spring 39 is provided between the nut 40 screwed on the pin 38 and the bracket 37 outside the bracket 37. Thus, a frictional force is generated between the brackets 36 and 37 and the pin 38 by the disc springs 39 and 39, so that it does not easily rotate. When the bonnet 3 is closed, the seat 4 also rotates integrally with the bonnet 3. In addition, even when the seat 4 is tilted forward, even if the backhoe is inclined with the rear portion facing downward, the seat 4 tilted forward does not fall backward.

Finally, an opening / closing structure of a battery cover disposed in the bonnet 3 will be described with reference to FIG. The battery BT is disposed in the main body frame 2 as shown in FIG. 29, and an upper portion thereof is attached with a battery cover 41 that can be easily opened and closed for easy maintenance. The battery cover 41 is attached to the main body frame 2. It has a function of blocking the internal circulation path of engine waste heat from the main body frame 2 into the hood 3 that also serves as the engine room. The battery cover 41 is opened and closed by turning in the horizontal direction. That is, the vertical rotation shaft 42 is disposed on the main body frame 2, and the battery cover 41 is pivotally supported so as to be able to rotate in the horizontal direction around the rotation shaft 42.

In a normal state where the battery BT is covered, the wing bolt 43 is fastened to the upper surface of the main body frame 2. During maintenance of the battery BT, the bonnet 3 is rotated upward, the butterfly bolt 43 is removed, and the battery cover 41 is rotated. At this time, the battery cover is placed outside the outer end of the bonnet 3 in the closed state. 41 is present. Thus, even if the hood 3 is rotated and closed while the battery cover 41 is opened, the battery cover 41 is not interposed between the main body frame 2 and the lower end of the hood 3 so as to be closed. Therefore, the user always notices that the battery cover 41 is forgotten to be closed. By keeping the battery cover 41 open and the upper part of the battery BT open, the circulation of waste heat from the main body frame 2 into the bonnet 3 is avoided. And overheating of the engine is also prevented.

  The overall configuration of the backhoe will be described with reference to FIG. A main body frame 2 is rotatably mounted on the crawler traveling device 1, and a bonnet 3 serving as an engine room is disposed at the rear of the upper portion of the main body frame 2. 4 is arranged. Further, in front of the bonnet 3, the upper end of the main body frame 2 is a step portion 2a, and a front column 5 is erected at the front end.

  A boom bracket 6 is pivotally supported at the front end projecting portion of the main body frame 2 so as to be horizontally rotatable, the boom 7 base end at the boom bracket 6 upper end, the arm 8 base end at the boom 7 front end, and the arm 8 A bucket 9 is pivotally supported at the tip, and these constitute a work arm. A blade 10 protrudes behind the crawler traveling device 1.

  In the backhoe having the above configuration, the boom 7, arm 8, bucket 9, and blade 10 that are working arms are respectively a boom cylinder C 1, an arm cylinder C 2, a bucket cylinder C 3, and a blade cylinder C 4 (illustrated in FIG. 22) that are hydraulic actuators. ) Is driven to rotate. Further, the turning of the boom bracket 6 with respect to the main body frame 2 and the turning of the main body frame 2 with respect to the crawler traveling device 1 are performed by driving a hydraulic motor. Further, the boom 7 is provided with a hydraulic pressure take-out port 21 from which pressure oil can be taken out and an attachment (breaker or the like) can be attached. The crawler travel device 1 also has a configuration in which the left and right drive wheels 1a and 1a around which the crawlers 1b and 1b are wound are driven by independent hydraulic motors (travel hydraulic motors ML and MR described later).

  These hydraulic drive devices are a combination of a plurality of control hydraulic valves disposed in the front column 5 as shown in FIGS. 3 and 4 from a hydraulic pump disposed in the main body frame 2. Pressure oil is supplied through a control valve CV. The backhoe of this embodiment is independent of the hydraulic motors P1 and P2 with respect to the left and right traveling hydraulic motors ML and MR, as shown in FIG. 2, in order to drive the driving wheels 1a and 1a of the left and right crawlers independently. In addition, the hydraulic oil supply is received, and the hydraulic drive devices are driven by the hydraulic sources of the two hydraulic pumps P1 and P2 for cost reduction and compactness. Therefore, in the control valve CV, the pressure oil supply circuit from the hydraulic pumps P1 and P2 is branched to each control hydraulic valve. It should be noted that the pressure oil supply circuit of the present case can be established with only one or one hydraulic pump.

  The traveling drive hydraulic system of the crawler traveling apparatus 1 will be described with reference to FIG. 2. From the hydraulic pump P1, the left traveling hydraulic motor ML is controlled via the left traveling control valve DVL in the control valve CV, and the hydraulic pump P2 controls the same. Pressure oil is supplied to the right traveling hydraulic motor MR via the right traveling control valve DVR in the valve CV. Both travel control valves DVL and DVR supply and discharge pressure oil to the return hydraulic circuit R6 common to the travel hydraulic motors ML and MR and the control valve CV in order to advance, reverse, and stop the drive wheel 1a. It is configured as follows. A crawler traveling device 1 and a traveling frame 2 are connected with a hydraulic system on the traveling frame 2 side and a hydraulic system on the crawler traveling device 1 side through a swivel joint SJ.

  In this traveling drive system, the left and right traveling hydraulic motors ML and MR are each provided with a movable swash plate, and the gears can be shifted to two stages of first speed and second speed by switching them to two positions. The movable swash plate is switched to the two positions by the pilot valves PVL and PVR, respectively. The hydraulic pressure supply for operating the movable swash plate from each pilot valve is supplied to each travel control valve DVL and DVR and each travel hydraulic motor ML.・ It is performed from the hydraulic circuit between MR. If the two-stage switching of the movable swash plate is not performed at the same time, a difference occurs in the rotational speeds of the left and right drive wheels at the time of shifting, causing unnecessary traveling turning. Therefore, the pilot pressure to both pilot valves PVL and PVR is taken from a return oil merging circuit R6 in which the return oil circuits of both the traveling hydraulic motors ML and MR are merged. That is, when a pilot pressure is established in the return oil merging circuit R6, the pilot pressure of the same pressure is simultaneously applied to both pilot valves PVL and PVR.

  In the return oil merging circuit R6, a pilot pressure is set when the second speed is set. Therefore, the branch circuits R3 and R4 for the pilot are branched from the discharge circuits R1 and R2 from the hydraulic pumps P1 and P2, respectively, and are merged in the merge circuit R5 for the pilot, and via the two-stage shift electromagnetic valve SV, The return oil merging circuit R6 is connected. Each of the pilot branch circuits R3 and R4 is provided with a check valve 11 that allows only the flow from the pump side to the pilot junction circuit R5. Since the check valve 11 regulates the amount of pressure oil flowing from the discharge circuits R1 and R2 to the pilot branch circuits R3 and R4, the amount of oil in the main flow of the pump is not reduced below the required amount. Absent. The two-stage speed change electromagnetic valve SV is configured to switch to the second speed when the electromagnetic solenoid is ON. At the first speed, the pilot merging circuit R5 and the return oil merging circuit R6 do not communicate with each other. The return oil is recovered from the junction circuit R6, and at the time of the second speed, the pilot junction circuit R5 and the return oil junction circuit R6 are connected to each other so that the pilot pressure is supplied from the pilot junction circuit R5 to the return oil junction circuit R6. Supply oil.

  As described above, the pressure oil is supplied to the two-stage speed change electromagnetic valve SV from the pilot junction circuit R5 in which the pressure oils from both the hydraulic pumps P1 and P2 are joined, and the hydraulic pumps P1 and P2 are also supplied to the hydraulic pumps P1 and P2. Therefore, since the backflow of the pressure oil does not occur in the check valves 11 and 11, the loss of the discharge pressure is not biased to either of the hydraulic pumps P1 and P2 with the two-stage speed change operation. Since the amount of pressure oil supplied to the left and right traveling control valves DVL and DVR is kept uniform, the crawler traveling device 1 does not perform an unintentional traveling turn.

  Conventionally, there is a configuration in which the pilot pressure oil at the second speed to the return oil merging circuit R6 is taken out from the return oil circuit of the control valve CV, and in this case, there is a problem that hydraulic pressure from the return oil side is applied to the control valve CV. However, in this embodiment, since it is not configured to take out from this portion, there is no possibility that the hydraulic pressure from the return oil side is applied to the control valve CV and causes a loss of engine output.

  A description will be given of an embodiment in which the above-described two-speed transmission hydraulic circuit is employed in a backhoe having a control valve CV shown in FIG. In the control valve CV, pressure oil is supplied from the hydraulic pump P1 to the left travel control valve DVL via the discharge circuit R11. The pressure oil supply circuit R12 is supplied from the upper discharge circuit R11 of the travel control valve DVL. The return oil circuit R13 is branched to supply pressure oil to the plurality of control valves from the pressure oil supply circuit R12, and the return oil circuit R13 becomes a common return oil circuit when all the control valves are neutral. Yes. Further, a discharge circuit R14 is piped from the hydraulic pump P2 into the control valve CV, and a pressure oil supply circuit R15 and a return oil circuit R16 are branched from the discharge circuit R14. Pressure oil is supplied to a plurality of control valves including the DVR, and the return oil circuit R16 is a common return oil circuit when all the control valves are neutral, and communicates with the return oil circuit R13.

  A check valve 11a that allows only the flow to the lower side is provided at the lower end of the pressure oil supply circuit R12, and a check valve 11b that also allows only the flow to the lower side at the lower end of the pressure oil supply circuit R15. A junction circuit R17 is interposed between the check valves 11a and 11b. Since each of the travel control valves DVL and DVR is supplied with pressure oil from the upper side of the check valves 11a and 11b, it is supplied with pressure oil independently of the hydraulic pumps P1 and P2. From P2, pressure oil is independently supplied to the traveling hydraulic motors ML and MR via the traveling control valves DVL and DVR, respectively. Thus, for example, if the left travel control valve DVL is set to the neutral stage and the right travel control valve DVR is set to the forward stage, the crawler travel device 1 can be turned forward and the left and right drive wheels 1a and 1a are independently provided. By driving it, a turning operation becomes possible.

  Then, pressure oil is supplied from the junction circuit R17 to the PTO control valve V1 and the blade control valve V2. That is, both control valves V1 and V2 are supplied with pressure oil from both hydraulic pumps P1 and P2. The blade control valve V2 can switch the driving of the hydraulic actuator for vertical rotation of the blade to three stages of an ascending stage, a descending stage, and a stopping stage, but the PTO control valve V1 applies pressure to the PTO terminal. There are only two stages, the stage for supplying oil and the stage for stopping the supply of pressure oil, and therefore, the attachment AT attached to the PTO terminal is of a driving structure such as a single-acting cylinder.

  Here, when considered as an application of the two-speed transmission hydraulic circuit shown in FIG. 2, the merging circuit R17 corresponds to the pilot merging circuit R5. Pressure oil may be supplied to the valve SV. For example, the pressure oil may be taken out from the merging circuit R17 from the pressure oil supply circuit to the blade control valve V2. In the embodiment of FIG. 5, when PTO is not driven, pressure oil is supplied from the PTO control valve V1 to the two-stage shift electromagnetic valve SV, and the switching operation of the PTO control valve V1 and the two-stage shift electromagnetic valve It is assumed that the pressure oil supply to the SV and the switching operation thereof are linked.

  More specifically, in the backhoe of this embodiment, in order to reduce the size and reduce the cost by reducing the number of operation members, the two-step traveling shift can be performed by the operation pedal 12 for PTO operation shown in FIGS. 3 and 4. Yes. The linkage structure between the operation pedal 12, the PTO control valve V1, and the two-stage shift electromagnetic valve SV will be described. The operation pedal 12 is bent in the shape of an eight character in the upper part of the front view. When the black arrow is pressed as shown in FIG. 4, the second speed is achieved, and when the white arrow is pressed, pressure oil is supplied to the PTO terminal. An attachment AT such as a breaker attached to the terminal can be driven. When the foot is returned, the state naturally returns to the state shown in FIG. 4, the traveling speed is the first speed, and the PTO is in the non-driven state.

  A connection structure between the operation pedal 12, the PTO control valve V1, and the two-stage shift electromagnetic valve SV will be described with reference to FIG. The base end portion of the operation pedal 12 is rotatably fitted to the horizontal pivot shaft 13, and the mounting plate 12b and the pressing element 12a are projected from the external fit portion of the operation pedal 12 base end. ing. Further, an electromagnetic valve control switch 14 is disposed near the base end of the operation pedal 12, and when the black arrow portion of the operation pedal 12 is pressed, the pressing element 12a is used for controlling the electromagnetic valve. The switch 14 is pressed and turned on, and the two-speed shift electromagnetic valve SV in the control valve CV is switched to the second speed.

  On the other hand, a mounting plate 17 is disposed in the vicinity of the control valve CV in the front column 5, and a pivot shaft 17a is projected from the mounting plate 17, and a boss 16 is externally fitted to the pivot shaft 17a. is doing. The connecting plate 16b is connected to the end of the spool 18 of the PTO control valve V1 in the control valve CV from the boss 16, and one end of the connecting rod 15 is pivotally supported on the mounting plate 12b of the operation pedal 12. The other end of 15 is connected to a connecting plate 16 a protruding from the boss 16.

  In this configuration, when the black arrow portion of the operation pedal 12 shown in FIG. 4 is stepped on, the connecting rod 15 is pushed to the boss 16 side, and the connecting plate 16b rotates downward together with the boss 16 as shown in FIG. 18 is pushed upward, and the PTO control valve V1 stops supplying pressure oil to the PTO terminal and enters a state in which pressure oil is supplied to the two-stage shift electromagnetic valve SV. In this state, the electromagnetic valve control switch 14 is turned ON, and the two-speed shift electromagnetic valve SV is in the second speed, so that the pilot pressure oil is supplied to the pilot valves PVL and PVR, and the left and right hydraulic motors ML The movable swash plate of MR is set to the second gear position. On the other hand, when the white arrow portion of the operation pedal 12 shown in FIG. 4 is stepped on, the connecting rod 15 is pulled toward the mounting plate 12b, the spool 18 is pulled downward, and the PTO control valve V1 is Then, the pressure oil is supplied to the PTO terminal, and the return oil is recovered from the two-stage shift electromagnetic valve SV. At the first speed, the state of the PTO control valve V1 is the same as that at the second speed, and pressure oil is supplied to the two-speed electromagnetic valve SV. However, the two-speed electromagnetic valve SV is set to the first speed. Therefore, the supply of pressure oil to the pilot valves PVL and PVR is cut off.

  The backhoe hydraulic control system centering on the two-speed shift control is as described above. Next, the piping structure of the hydraulic pressure takeout hose will be described with reference to FIGS. The boom 7 of the backhoe is provided with hydraulic outlets 7a and 7a near the ends of both side plates. In addition to the cylinder hoses CH and CH for the arm cylinder C2 and bucket cylinder C3, Pressure oil extraction hoses PH and PH (one for pressure oil supply and the other for pressure oil discharge) can be piped. As shown in FIGS. 9 to 11, at each hydraulic outlet 7a and 7a, a hydraulic outlet port 21 is fitted and fastened with a bolt 20 inside the side plate of the boom 7, and the hydraulic outlet port 21 is connected to the hydraulic outlet port. It protrudes to the outside from the outlet 7a. A connector 19 is attached to the end of the pressure oil take-out hose PH inside the boom 7 and is connected to the oil pressure take-out port 21 via the connector 19.

  The boom 7 is bent in the shape of a "<" in a side view at the center portion, but the portion on the base end side from the bent portion is configured in a box shape, that is, a quadrangular shape in cross section. The portion on the more distal end side is notched on the back side, and on the inner side of the boom, an intermediate rib plate 22 is disposed in parallel with the abdominal surface, and an arm cylinder C2 is disposed above the intermediate rib plate 22. . As shown in FIG. 8, the hydraulic take-out hose PH is piped from the body frame 2 side at the base end of the boom 7 and is inserted into the boom 7 through a hose insertion hole 7b drilled in the rear side of the boom 7 base end. is doing. And in the boom 7, with the cylinder hose CH, it is being fixed by clamp member A * B by the base end part vicinity and this bending part of a center part.

  The hose fixing structure by the clamp member A at the boom base end will be described with reference to FIGS. A hose guide plate 23 is disposed inside the boom 7 below the hose insertion hole 7b, and a clamp member A is fixed on the hose guide plate 23. The hose PH is also fixed. The hose guide plate 23 also has a function of reinforcing the base end portion of the boom 7 whose strength is weakened by forming the hose insertion hole 7b on the back side.

  The configuration of the clamp member A will be described. On the hose guide plate 23, rubber clamps 24 and 25 are arranged in two stages. The lower rubber clamp 24 is provided with cylinder hose fitting insertion holes 24a, 24a, and the upper rubber clamp 25 is provided with hydraulic extraction hose fitting insertion holes 25a, 25a. The respective hose insertion holes 24a and 25a can be inserted into the respective insertion holes 24a and 25a by making a cut and pushing the hose into the cut. As shown in FIGS. 12 and 15, the rubber clamp 24 is attached by fitting a mounting plate 26 fixed on the hose guide plate 23 into a groove at the lower end, and a gate-shaped lower stage fixing bracket 27 is mounted thereon. Overlapping. The rubber clamp 25 is placed on the lower fixing bracket 27 and a portal-shaped upper fixing bracket 28 is overlaid thereon. A bolt hole is drilled at the upper end of the upper fixing bracket 28, and a female screw 29 is penetrated from the bolt hole to the mounting plate member 26 at the lower end, and a bolt 30 is screwed into the female screw 29. The hydraulic hoses CH and PH are piped through the fitting insertion holes 23a and 24a of the rubber clamps 23 and 24, respectively.

  Further, as shown in FIGS. 13 and 14, a hose presser 31 having a U-shape in plan view is projected rearward from both sides of the lower clamp 26, and the lower cylinder hose CH piped on the hose guide plate 23 is provided. Is pressed from above as shown in FIG. On the other hand, a hose presser 32 is installed on the inner side of the boom at the front end of the hose insertion hole 7b, and the hydraulic takeout hose PH that has passed through the rubber clamp 25 is pressed from above as shown in FIG. Thus, in the vicinity of the rubber clamps 24 and 25, the hydraulic hose is bent more than necessary so that it cannot be removed from the fitting holes 24a and 25a of the respective rubber clamps.

  Next, the hose fixing structure by the clamp member B at the “K” bent portion of the boom 7 will be described with reference to FIGS. 16 to 20. In the boom bent portion, the rear end of the middle rib plate 22 is bent into an L shape and connected to the rear end of the notch portion on the back side. In the L-shaped bent portion of the middle rib plate 22, a hose fitting insertion hole 22a is formed as shown in FIG. 18, and parallel to the abdominal surface of the middle rib plate 22 slightly closer to the tip than the hose fitting insertion hole 22a. A clamp stopper 22b is protruded from this portion. A rubber clamp 33 shown in FIG. 19 is inserted between the hose insertion hole 22a and the clamp stopper 22b. The rubber clamp 33 has two upper and lower hose insertion holes. The upper part has large diameter insertion holes 33a and 33a for insertion of the hydraulic take-out hose PH. Are provided with small-diameter fitting insertion holes 33b, 33b,... Of cylinder hoses CH for arm cylinders and bucket cylinders. Cuts are provided in the fitting insertion holes 33a and 33b from the outside of the rubber clamp 33, and a hose is embedded in the cuts, and hydraulic hoses are fitted into the fitting insertion holes 33a and 33b. Further, in order to fix the rubber clamp 33, the fixing bracket 34 shown in FIG. 20 presses the rubber clamp 33 from above. Screw holes 34a and 34a are formed above the fixing bracket 34, and bolts 35 and 35 are screwed into the screw holes 34a and 34a and the female threads 22c and 22c of the intermediate rib plate 22, respectively. Is fixed to the L-shaped bent portion of the middle rib plate 21. In this way, the cylinder hose CH and the hydraulic take-out hose PH are fixed by piping by the clamp member B at the “K” -shaped bent portion of the boom 7.

  As described above, not only the cylinder hose CH but also the hydraulic takeout hose PH previously piped to the outer surface of the boom can be piped in the boom 7 and can be easily combined with the cylinder hose CH with the clamp members A and B. Moreover, the pipe can be fixed in a compact manner, and on the outer side of the boom, only the hydraulic take-out port 21 protrudes from the hydraulic take-out port 7a. Interference with objects is avoided.

  Next, each part structure in the main body part of the backhoe comprised with the main body frame 2, the bonnet 3, the seat 4, and the front column 5 shown in FIG.21 and FIG.22 is demonstrated. First, the arrangement structure of the starter switch in the front column 5 will be described with reference to FIGS. The conventional starter switch that is inserted into the key K to start the engine is conventionally in a state in which the inserted key protrudes linearly rearward, that is, toward the operator sitting on the seat. However, the backhoe according to the present embodiment is assumed to be small, and the front column 5 is also small. Therefore, the knee KN of the worker sitting on the rear seat 4 is also as shown in FIGS. In the vicinity of the front column 5. Conventionally, the key hole of the starter switch SS faces the rear of the front column 5, and the inserted key K projects rearward as shown in FIG. 26, so that there is a problem that the operator hits the foot when getting on and off. . Furthermore, since the left-right width of the front column 5 is short, the starter switch SS is close to the side end portion of the front column 5 as shown in FIG. Therefore, it is in contact with the knee KN of the worker who is sitting on the seat and working. If the key hole position is shifted toward the center of the front column 5 so as to avoid contact with the knee KN, this time, the key is moved away from the hand position, making it difficult to insert and remove the key.

  Therefore, as shown in FIGS. 23 to 25, the rear end vertical surface of the front column 5 is recessed in the shape of a “<” inwardly in a plan view to form a recess 5 a and the recess 5 a is inclined in plan view. The starter switch SS is attached to the inner surface of the shaped surfaces, and the key holes are arranged in the outwardly inclined direction in plan view. Thus, the inserted key K is inclined in a plan view in the inner concave portion 5a, and therefore, the portion protruding rearward from the vertical portion of the rear end of the front column 5 is very small, and getting on and off. Less interfere with the operator's feet. Further, since the key hole position is shifted from the vicinity of the side end portion of the front column 5 as in the prior art to the center portion, it does not come into contact with the knee KN of the worker who is working. Further, as described above, even when the key hole position is closer to the center part (inner side) of the front column 5, the key hole faces the outer side inclined shape in plan view, so that it is outside the side end part of the front column 5. It is easy to insert and remove the key K by hand.

1 is an overall side view of a backhoe according to the present invention. It is a hydraulic circuit diagram for driving | running | working drive which enables two speed shifting. It is a front view which shows the connection structure of the operation pedal 12 and front column CV of a backhoe. FIG. 4 is a partially enlarged front view of FIG. 3. FIG. 3 is a hydraulic circuit diagram in which the traveling drive hydraulic circuit shown in FIG. 2 is applied to a backhoe control valve CV. FIG. 6 is a hydraulic circuit diagram at the second speed stage in the hydraulic circuit shown in FIG. 5. FIG. 6 is a hydraulic circuit diagram during PTO driving in the hydraulic circuit shown in FIG. 5. It is a side view of the work arm part of the backhoe which piped the hose PH for hydraulic extraction inside the boom. It is a XX arrow line view in FIG. It is a partial plane fragmentary sectional view of the boom which shows the arrangement structure of a hydraulic extraction port. It is a partial side view similarly. It is an internal side view which shows the piping structure of the hydraulic extraction hose and cylinder hose in a boom base end part. It is also an internal plan view. It is a top view which shows the arrangement | positioning structure of the clamp member A in a boom base end part. It is a front sectional view similarly. It is an internal side view which shows the piping structure of the hydraulic extraction hose and cylinder hose in a boom bending part. It is an internal top view which shows the arrangement | positioning structure of the clamp member B in a boom bending part. It is an internal front view similarly. 3 is a perspective view of a rubber clamp 33. FIG. FIG. 6 is a perspective view of a fixing bracket 34. It is a side view of a backhoe main-body part. It is also a plan view. It is a rear view of the front column 5 showing the arrangement structure of the starter switch SS. It is a YY arrow line view similarly in FIG. Similarly, it is an internal side view of the front column 5. FIG. It is a side view of the backhoe main-body part which shows the arrangement structure of the conventional starter switch. Similarly, it is a Y'-Y 'arrow view in FIG. 3 is a side view of a backhoe main body showing an opening / closing structure of a bonnet 3. FIG. Similarly it is a rear view. 3 is a partial front sectional view showing a mounting structure of a seat 4 with respect to a bonnet 3. FIG. It is a fragmentary front sectional view which similarly shows the conventional attachment structure. 4 is a plan view of a backhoe main body showing an opening / closing structure of a battery cover 41. FIG. FIG. 6 is a hydraulic circuit diagram at the first speed stage of a hydraulic circuit configured to extract a pilot pressure for two-speed shifting from a return oil circuit common to a conventional control valve CV. FIG. 3 is a hydraulic circuit diagram at the second speed stage.

Explanation of symbols

P1 / P2 Hydraulic pump ML / MR Driving hydraulic motor CV Control valve DVL / DVR Traveling control valve PVL / PVR Two-stage shifting pilot valve SV Two-stage shifting solenoid valve V1 PTO control valve R1 / R2 Discharge circuit R3 / R4 Pilot Branch circuit R5 Pilot confluence circuit PH Hydraulic take-out hose CH Cylinder hose BT Battery A / B Clamp member 1 Crawler traveling device 1a Drive wheel 2 Body frame 3 Bonnet 4 Seat 5 Front column 7 Boom 7a Hydraulic outlet 7b Hose insertion Hole 11 Check valve 19 Connector 21 Hydraulic take-out port 22 Middle rib plate 22a Hose insertion hole 23 Hose guide plate 24/25 Rubber clamp 27 Lower fixing bracket 28 Upper fixing bracket 33 Rubber clamp 34 Fixing bracket 1 battery cover

Claims (1)

In a configuration in which a battery is disposed in the body frame of the backhoe, opened and closed by rotating up and down on the body frame, and a bonnet for housing the engine is attached, It has a pin that is a moving shaft, and the rear part of the bonnet is configured to be openable by rotating upward, enabling maintenance of the engine housed in the bonnet and the battery disposed in the main body frame, A battery cover that covers the upper part of the battery is configured to open and close by rotating in a horizontal direction around a vertical rotation axis disposed on the main body frame, and when the battery cover is opened, the battery cover Projecting outward from the main body frame, and with the battery cover opened, the bonnet is rotated downward to close the bonnet. , Backhoe, characterized in that the battery cover between the body frame and the bonnet is constructed impossible closed interposed.

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