JP4973144B2 - Construction machinery - Google Patents

Description

  The present invention relates to a construction machine such as a hydraulic excavator in which a hydraulic oil tank and a control valve are installed side by side.

  The background art will be described taking a hydraulic excavator as a preferred example of the present invention as an example.

  As shown in FIG. 5, the hydraulic excavator is configured such that an upper swing body 2 is rotatably mounted on a crawler-type lower traveling body 1 and a work attachment 3 is mounted on the upper swing body 2.

  The work attachment 3 includes a boom 4 that can be raised and lowered, an arm 5 attached to the tip of the boom 4, a bucket 6 attached to the tip of the arm 5, and a boom and an arm that are hydraulic actuators for driving them. And bucket cylinders 7, 8, and 9.

  FIG. 6 shows a part of the equipment arrangement in the upper swing body 2 of the hydraulic excavator, and FIG. 7 further shows a part thereof in an enlarged manner.

  As shown in the figure, an engine 10 as a power source and a hydraulic pump 11 as a hydraulic power source are installed at the rear part of the upper frame 12 serving as a base of the upper swing body 2, and the left and right sides (in the illustrated example) in front of these. On the right side, a control valve 13 for controlling the operation of the hydraulic actuators such as the hydraulic cylinders 7 to 9 and a hydraulic oil tank 14 for supplying hydraulic oil to the hydraulic actuators are installed side by side with the control valve 13 outside. Is done.

  A guard cover 15 is attached to the right end of the upper frame so as to be openable / closable around the front side, and maintenance of the control valve 13 is performed by opening the guard cover 15.

  As shown in FIG. 7, the control valve 13 has a plurality of main spools 16 (only one is shown in the figure) 16 for controlling the operation direction and speed based on lever operation for each actuator in one valve block 17. It is built in a hierarchy.

  In the control valve 13, the main spool 16 is provided in parallel to the hydraulic oil tank 14, that is, in the front-rear direction for convenience of piping connection to each port.

  In addition, when a so-called pressure compensation function that compensates for the operating pressure of the hydraulic actuator and ensures a certain operability regardless of load fluctuations is required, a pressure compensation spool (also referred to as a load sensing spool) 18 is connected to the main spool 16. It is provided in the right angle direction, that is, in the left-right direction.

  In FIG. 7, reference numeral 19 denotes a bolt that closes the inlet / outlet of the pressure compensation spool 18, and the pressure compensation spool 18 is attached to and detached from the valve block 17 with the bolt 19 removed during valve assembly and maintenance.

  On the other hand, the configuration of a conventional hydraulic oil tank 14 is shown in FIGS.

  The hydraulic oil tank 14 is provided with a bottomed cylindrical filter case 21 in the tank body 20 to house a return filter 22 therein, and return return oil returning from the hydraulic actuator through a plurality of return pipes 23. After filtering with the filter 22, it is the structure which returns in the tank main body 20 with the return pipe 24 penetrated by the center part of the filter case bottom wall 21a.

  The return filter 22 is placed on the bottom wall 21 a of the filter case 21 and is held by the pressing spring 25.

  In the figure, 26 is a suction filter for filtering feed oil, and 27 is a suction pipe.

  In this tank structure, conventionally, as shown in the figure, all return pipes 23 are connected above the return filter 22, that is, above the filter case side wall 21b.

Among the above configurations, the control valve 13 and the hydraulic oil tank 14 are arranged in parallel in Patent Document 1, the control valve structure including the pressure compensation spool 18 is in Patent Document 2, and the configuration of the hydraulic oil tank 14 is in Patent Document. 3 respectively.
JP-A-11-190449 Japanese Patent Laid-Open No. 2002-13656 JP 2005-282805 A

  6 and 7, when the control valve 13 is maintained, the main spool 16 can be easily attached and detached in the front-rear direction by the space on both the front and rear sides, but the pressure compensation spool 18 can be attached and detached. Since the left-side space S on the work side is closed with the hydraulic oil tank 14, the attachment / detachment work becomes difficult or impossible as it is.

  For this reason, the entire control valve 13 has to be removed from the upper frame 12 at the time of maintenance, and the work is very troublesome.

As a countermeasure,
(A) Shifting the hydraulic oil tank 14 inward (left side) to ensure a sufficient working space with the control valve 13;
(B) It is conceivable to reduce the hydraulic oil tank 14 in the left-right direction.

  However, the measure (A) is difficult to implement for a hydraulic excavator, particularly a small excavator such as a small swivel type, because the equipment installation space is limited.

  Further, according to the measure (B), the tank capacity of the hydraulic oil tank 14 is reduced, and a necessary amount of hydraulic oil cannot be secured, which is also difficult to realize.

  Note that it is conceivable to increase the effective capacity of the tank body 20 by reducing the size of the return structure such as the filter case 21 shown in FIGS.

  However, in the conventional hydraulic oil tank 14 as described above, all the return pipes 23 are concentrated on the upper part of the side wall of the filter case 21 and connected in a paw-foot shape, so that this pipe connection area can be secured. The circumference of the filter case 21 must be increased. As a result, it is practically impossible to reduce the diameter of the case 21, and this has become an obstacle, making it difficult to reduce the size of the tank.

In view of the circumstances described above, is installed side by side hydraulic oil tank and control valve, and the control valve, in the context of pressure compensation spool tanks ing and failure of the detachable is incorporated, hydraulic oil A construction machine capable of reducing the size of a tank and ensuring a sufficient working space for attaching / detaching a spool to / from a control valve, and also ensuring a necessary tank capacity.

The invention of claim 1 has all the following requirements.

  (A) Provide a control valve for controlling the operation of the hydraulic actuator and a hydraulic oil tank.

  (B) The control valve includes a main spool that controls the operating direction and speed of the hydraulic actuator, and a pressure compensating spool that is provided in a direction perpendicular to the main spool and compensates the operating pressure of the hydraulic actuator. Is installed side by side with the hydraulic oil tank in a state where the working oil tank is parallel to the hydraulic oil tank and a work space necessary for attaching and detaching the pressure compensation spool is formed between the hydraulic oil tank and the hydraulic oil tank.

  (C) Of the valve facing surface facing the control valve in the tank body of the hydraulic oil tank, only the portion from the intermediate portion to one end facing the pressure compensation spool is inclined away from the control valve toward the one end. The above-mentioned work space is formed to be widened in one direction and partially by being recessed in a planar shape.

  (D) A filter case that houses a return filter for filtering the return oil is provided in the tank body of the hydraulic oil tank, and a plurality of return pipes are connected to the side wall of the filter case in a vertically dispersed manner.

According to a second aspect of the present invention, in the configuration of the first aspect , a filter receiving plate is provided at a lower portion in the filter case of the hydraulic oil tank with a space between the filter case bottom wall and the return filter. Provided on this filter receiving plate, a plurality of return pipes are vertically distributed and connected to the side wall of the filter case below the filter receiving plate at the lower part .

According to the present invention, by recessing the valves facing surface of the tank main body of the hydraulic oil tank, since to form a working space required for attachment and detachment of the pressure compensating spool between the tank and the control valve, the pressure The compensation spool can be easily attached and detached by this work space.

In this case, only the portion from the intermediate portion facing the pressure compensation spool to the one end of the valve facing surface is recessed into an inclined surface shape away from the control valve toward the one end, so that the work space is partially In addition, since it is formed to expand toward one direction, the capacity reduction of the tank can be minimized while securing the necessary work space, compared with the case where the middle part of the tank surface is recessed as a recessed part. . In addition, the tank can be easily processed.

  In addition, the return pipes are connected to the filter case so that the working space is secured because the filter case can be made smaller (smaller diameter) and the effective capacity of the tank body can be increased accordingly. Therefore, it is possible to secure the necessary tank capacity by covering the portion where the valve facing surface is recessed.

  In addition, since the restriction of the return piping is relaxed by being dispersed above and below the return piping, the shape and connection structure of the return piping are simplified, which is advantageous in terms of manufacturability and cost. The effect of this point is particularly noticeable in a small tank mounted on a small excavator.

  On the other hand, since the return oil can be introduced and filtered from both the upper and lower sides of the return filter, the filtration surface of the filter can be widely used. For this reason, the lifetime of the filter can be improved.

  By the way, if a part of the return pipe is connected to the lower part of the filter case, the return oil from this lower pipe (especially the high-pressure oil of the main pipe) may directly hit the side of the filter, and the pressure may damage the filter surface (filter paper). is there.

In this regard, according to the second aspect of the present invention, the filter receiving plate is provided in the lower part of the filter case, and the filter is installed in a state of being floated from the bottom wall of the case. It is possible to connect return piping while avoiding direct hits.

  In other words, the return pipes are connected in an up-and-down manner without causing the harmful effect of the filter side being damaged by direct hitting of the return oil or the complicated structure of installing a baffle plate at the return oil introduction part to avoid this. It becomes possible.

  An embodiment of the present invention will be described with reference to FIGS. In the embodiment, a hydraulic excavator is taken as an example of application.

  1 and 2 show a part of the equipment arrangement of the upper frame 12 and correspond to the prior art shown in FIGS.

The basic configuration of this embodiment, i.e.
(I) The engine 10 and the hydraulic pump 11 are installed at the rear of the upper frame 12, and the control valve 13 and the hydraulic oil tank 28 are arranged side by side on the right side in front of them.
(Ii) The guard cover 15 is attached to the right end of the upper frame so as to be openable / closable around the front side, and maintenance of the control valve 13 and the hydraulic oil tank 28 is performed by opening the guard cover 15;
(Iii) The control valve 13 is configured such that a plurality of main spools 16 (only one is illustrated) are incorporated in a single valve block 17 in a hierarchical manner,
(Iv) The main spool 16 is provided in parallel (front-rear direction) with the hydraulic oil tank 28;
(V) The pressure compensation spool 18 is provided perpendicular to the main spool 16, and the spool 18 is attached / detached by the work space S with the hydraulic oil tank 28 with the bolt 19 removed. The same.

  On the other hand, FIGS. 3 and 4 showing the configuration of the hydraulic oil tank 28 correspond to the prior art shown in FIGS.

  The basic structure of the hydraulic oil tank 28 is the same as that of the prior art. A bottomed cylindrical filter case 30 is mounted in the tank body 29 to house a return filter 31 therein, and a plurality of return pipes 32 are provided from the hydraulic actuator. The return oil that flows back through is filtered by the return filter 31 and then returned to the tank body 29 by a return pipe 33 penetrating through the center of the filter case bottom wall 31a.

  The return filter 31 is placed on the bottom wall 30 a of the filter case 30 and is held by the pressing spring 34. In the figure, 35 is a suction filter for filtering feed oil, and 36 is a suction pipe.

In this embodiment, as a difference from the prior art, first, the rear half of the valve facing surface (right side surface) 29a facing the control valve 13 in the tank body 29 of the hydraulic oil tank 28, that is, the attachment / detachment of the pressure compensation spool 18 is performed. The portion 29a1 forming the work space S required for the operation is recessed toward the rear end in an inclined surface shape in the direction away from the control valve 13 (inward), so that the work space S expands toward the rear side. Is formed.

  Thus, as can be seen in comparison with FIG. 7, the working space S is expanded more inward than in the prior art, and the bolt 19 and the pressure compensation spool 18 are expanded as shown by phantom lines in FIG. It is configured to be removable.

In other words, the valve-facing surface rear half portion 29a1 of the tank body 29 is recessed so that a work space S necessary and sufficient for attaching and detaching the pressure compensation spool 18 is formed between the control valve 13 and the hydraulic oil tank 28. Not.

  By doing so, the maintenance work of the pressure compensation spool 18 can be performed easily and efficiently without increasing the distance between the control valve 13 and the hydraulic oil tank 28 and without removing the control valve 13.

In addition, the entire valve facing surface ( right side ) 29a of the tank body 29 is not recessed, but only the rear half 29a1 that obstructs the attachment / detachment of the pressure compensation spool 18 is recessed, and the rear half is not recessed. Since the 29a1 is inclined in the direction away from the control valve 13, the capacity reduction of the tank body 29 due to the depression can be minimized while ensuring the necessary space in the work space S.

  Furthermore, in this embodiment, the hydraulic oil tank 28 is configured as follows in order to cover the decrease in the tank capacity.

  As shown in FIGS. 3 and 4, a filter receiving plate 37 is provided in the lower part of the filter case 30 with a gap A (see FIG. 3) between the filter case bottom wall 30a and a return filter 31 is provided. It is placed on the plate 37 and pressed and held by the pressing spring 34.

  The filter receiving plate 37 is attached to the upper end portion of the return pipe 33 penetrating the filter case bottom wall 30a in a state where the central portion is penetrated by the pipe 33, and one or a plurality (two in the illustrated example) of return pipes. 32 ... are connected to the lower part of the case side wall 30b below the filter receiving plate 37 (in the range of the interval A).

  In other words, a pipe-connectable portion is also formed at the lower part of the filter case side wall 30b, and the return pipes 32 are dispersedly connected to the upper and lower parts of the filter case side wall 30b.

  According to this configuration, compared to the case where all return pipes 23... Are concentrated on the upper part of the filter case side wall 21b and connected in a paw-like shape as in the prior art shown in FIGS. The required circumference of the filter case 30 can be shortened.

  For this reason, it is possible to reduce the diameter of the filter case 30 and to increase the effective volume of the tank body 30 to cover the portion where the right side surface 29a is recessed, that is, to secure the necessary tank capacity.

  Moreover, since the restriction of the connection of the return pipes 32 is eased by dispersing the return pipes 32 in the vertical direction, the shape and connection structure of the return pipes 32 are simplified, which is advantageous in terms of manufacturability and cost. Become. The effect of this point is particularly noticeable in a small tank mounted on a small excavator.

  On the other hand, since the return oil can be introduced and filtered from the upper and lower sides of the return filter 31, the filtration surface of the filter 31 can be widely used. For this reason, the lifetime of the filter 31 can be improved.

  Furthermore, since the return pipe 33 originally provided in the tank 28 is slightly extended and the filter receiving plate 37 is supported by the pipe 33, it is not necessary to add a dedicated member for supporting the plate 37. For this reason, it is advantageous for simplification of the tank structure, and there is no possibility that the flow of the hydraulic oil in the filter case 30 is hindered.

  By the way, even when the conventional tank structure shown in FIGS. 8 and 9 is assumed, a part of the return pipes 32 can be connected to the lower part of the filter case side wall 30b. However, if this is done, the return oil from the lower pipe (particularly the high-pressure oil in the main pipe) may hit the filter side face directly, and the pressure may damage the filter face (filter paper).

  In this respect, in this embodiment, since the filter receiving plate 37 is provided in the lower part in the filter case 30 and the filter 31 is installed in a state of floating from the case bottom wall 30a, the return oil to the side of the filter is provided in the lower part of the case. The return pipe 32 can be connected while avoiding the direct hit.

  In other words, it is possible to connect the return pipes 32 in an up-and-down manner without incurring the harmful effect of damaging the filter side face by direct hitting of the return oil, or taking a complicated structure to attach a baffle plate to avoid this. It becomes.

Other embodiments
The support structure of the filter receiving plate 37, for example like provided between the sparse same plates 37 support members mesh with the filter case bottom wall 30a, may be changed to others.

Alternatively, a configuration in which the return pipes 32 are divided into upper and lower parts and connected to the filter case 30 with the conventional return structure shown in FIGS. In this case, a configuration may be adopted in which a direct hit of the return oil against the lower side surface of the filter 31 is avoided by a known baffle plate .

1 is a schematic plan view showing an upper frame of a hydraulic excavator and a part of equipment arrangement according to an embodiment of the present invention. It is a figure which expands and shows a part of FIG. It is sectional drawing of the hydraulic oil tank in FIG. FIG. 4 is a partially enlarged view of FIG. 3. It is a schematic side view of a hydraulic excavator which is a preferred example of the present invention. FIG. 2 is a view corresponding to FIG. 1 for explaining the prior art. FIG. 3 is a view corresponding to FIG. It is sectional drawing of the conventional hydraulic oil tank. It is the IX-IX line expanded sectional view of FIG.

DESCRIPTION OF SYMBOLS 12 Upper frame of hydraulic excavator 13 Control valve 16 Main spool 18 Pressure compensation spool as a part which obstructs attachment / detachment of tank 19 Bolt 28 Hydraulic oil tank S Work space formed between control valve and hydraulic oil tank 29 Tank body 29a Right side facing the control valve (valve facing side)
29a1 Rear right half 30 Filter case 30a Filter case bottom wall 30b Filter case side wall 31 Return filter 32 Return pipe 33 Return pipe 37 Filter receiving plate A Distance between the filter case bottom wall and the filter receiving plate

Claims (2)

A construction machine characterized by having all the following requirements:
(A) a control valve for controlling the operation of hydraulic actuators, comprises a hydraulic oil tank.
(B) The control valve includes a main spool that controls the operating direction and speed of the hydraulic actuator, and a pressure compensating spool that is provided in a direction perpendicular to the main spool and compensates the operating pressure of the hydraulic actuator. Is installed side by side with the hydraulic oil tank in a state where the working oil tank is parallel to the hydraulic oil tank and a work space necessary for attaching and detaching the pressure compensation spool is formed between the hydraulic oil tank and the hydraulic oil tank.
(C) Of the valve facing surface facing the control valve in the tank body of the hydraulic oil tank, only the portion from the intermediate portion to one end facing the pressure compensation spool is inclined away from the control valve toward the one end. The above-mentioned work space is formed to be widened in one direction and partially by being recessed in a planar shape.
(D) A filter case that houses a return filter for filtering the return oil is provided in the tank body of the hydraulic oil tank, and a plurality of return pipes are connected to the side wall of the filter case in a vertically dispersed manner. A filter receiving plate is provided at the lower portion of the hydraulic oil tank in the filter case with a space between the filter case bottom wall, the return filter is provided on the filter receiving plate, and a plurality of return pipes are arranged vertically. 2. The construction machine according to claim 1, wherein the construction machine is connected to the side wall of the filter case at a lower portion and below the filter receiving plate at the lower portion .

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