JP2006183849A - Option valve device and its valve block - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simultaneously achieve both common use of valve blocks and overall compactness. <P>SOLUTION: An option valve device is composed of a pump block 21 into which pressure oil is introduced from a hydraulic pump and both a first and second valve blocks 22a, 22b equipped with a switching valve 32 for controlling flow of pressure oil feeded from the pump block 21. Both valve blocks 22a, 22b are respectively provided with pressure oil passages 27 through which pressure oil passes, center bypass passages 28 for bleed-off control, tank passages 29 and communicating passages 33 for connecting the center bypass passage 28 and the tank passage 29 on the downstream side of the switching valve 32, and opening/closing means for opening the communicating passage 33 of the second valve block 22b on the downstream side and blocking the communicating passage 33 of the first valve block 22a on the upstream side. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an optional valve device retrofitted to a main valve device in a construction machine such as a hydraulic excavator and its valve block.

  For example, in a hydraulic excavator, a bucket may be removed from a front attachment, and another working device such as a crusher (hereinafter referred to as an optional device) may be attached instead.

  In this case, an optional valve device for sending the pressure oil from the hydraulic pump to the hydraulic actuator of the optional device and controlling the operation is connected to the main valve device later.

  Conventionally, as shown in FIG. 5, this optional valve device includes a pump block 1 for introducing pressure oil from the hydraulic pump in order from the side closer to the hydraulic pump (upstream side), and this pump block. 1 is constituted by joining three blocks: a valve block 2 for controlling the flow of pressure oil sent from 1 and a tank block 3 for flowing oil through a tank passage (not shown) of the main valve device A.

  The pump block 1 is provided with a pressure oil passage 4, a center bypass passage 5 for bleed-off control branched from the pressure oil passage 4, and a tank passage 6, and a main relief valve 7 is provided in the tank passage 6. .

  The valve block 2 includes a pressure oil passage 8 communicating with the pressure oil passage 4 of the pump block 1, a center bypass passage 9, a tank passage 10, and actuator passages 11 and 12 connected to a hydraulic actuator (not shown). A switching valve 13 is provided across the passages 8 to 12.

  The tank block 3 is provided with a center bypass passage 14 and a tank passage 15 connected to the tank passage of the main valve device A, and the center bypass passage 14 is connected to the tank passage 15 (see Patent Document 1).

  On the other hand, when a plurality of optional devices (hydraulic actuators) are added, as shown in FIG. 6, a plurality of common products (here, a common product having the same configuration between the pump block 1 and the tank block 3). The valve blocks 2a and 2b (shown in two cases) are stacked in the flow direction of the pressure oil, and the corresponding passages are connected to each other.

5 and 6, P and Pp are pump ports, Pc is a center bypass port, A, A1, A2, B, B1 and B2 are actuator ports connected to hydraulic actuators, Pa, Pa1, Pa2, Pb, Pb1, Pb2 is a pilot port connected to a remote control valve (not shown), and T is a tank port.
JP 2001-355601 A

  However, according to the conventional option valve device configured by joining three blocks 1, 2, and 3 for each option device as described above, the overall length L of the entire device is increased, so that the occupied space is also increased.

  For this reason, it has been extremely disadvantageous in machines such as small hydraulic excavators that do not have enough space for installation of equipment.

  As a countermeasure against this point, it is conceivable to integrate two adjacent ones of the three blocks 1, 2, 3 (for example, the valve block 2 and the tank block 3). However, this integration makes the valve block 2 a dedicated product only for a specific optional device and makes it impossible to share the valve block 2, which is extremely disadvantageous in terms of cost and the like.

  Therefore, the present invention provides an optional valve device that can simultaneously realize both a common valve block and a compact device as a whole, and a valve block used in the optional valve device.

  The invention (optional valve device) of claim 1 is an optional valve device retrofitted to a main valve device for controlling the operation of an added hydraulic actuator, a pump block for introducing pressure oil from a hydraulic pump, The valve block is provided with a switching valve for controlling the flow of pressure oil sent from the pump block. The pressure oil passage through which the pressure oil passes, the center bypass passage for bleed-off control, and the main valve Provided with a tank passage connected to the tank passage of the apparatus and a communication passage connecting the center bypass passage and the tank passage downstream of the switching valve, and having an opening / closing means for opening / closing the communication passage It is.

  According to a second aspect of the present invention, in the configuration of the first aspect, the valve blocks are provided in a stack in the flow direction of the pressure oil in a state where a plurality of valve blocks, the pressure oil, the center bypass, and the tank passages communicate with each other. For the valve block on the downstream side, the communication passage is opened by the opening / closing means, and for the other valve blocks, the communication passage is blocked by the opening / closing means.

  According to a third aspect of the present invention, in the configuration of the first or second aspect, two center bypass passages and two tank passages of the valve block are provided symmetrically with respect to the block center, and the center bypass passage and the tank passage on both sides thereof are provided. Each has a communication passage between them.

  According to a fourth aspect of the present invention, in the structure according to any one of the first to third aspects, the open / close means is externally closed in a state where the communication passage is blocked by an opening provided in a side surface of the valve block in order to process the communication passage. It uses a plug that is removably screwed.

  According to a fifth aspect of the present invention (valve block), in a valve block of an optional valve device retrofitted to the main valve device, a pressure oil passage for passing pressure oil sent from the hydraulic pump through the pump block, and bleed-off control A center bypass passage, a tank passage connected to the tank passage of the main valve device, a switching valve for controlling the flow of pressure oil, and the center bypass passage and the tank passage on the downstream side of the switching valve. A communication passage for connecting the two is provided, and opening / closing means for opening / closing the communication passage is provided.

  According to the present invention, as a configuration in which the valve block and the tank block are integrated, a communication passage for connecting the center bypass passage and the tank passage of the valve block on the downstream side of the switching valve is provided, and the communication passage is opened and closed. In the case where there is a single valve block (Claim 1), the communication passage of the valve block is opened, and when there are a plurality of valve blocks (Claim 2), the most downstream side is opened. A circuit with a center bypass line can be configured to open only the communication passage of the valve block.

  That is, both the common use of the valve block and the compactness of the entire optional valve device can be realized simultaneously.

  By the way, in the optional valve device, as in the invention of claim 3, two center bypass passages and two tank passages of the valve block are arranged symmetrically with respect to the center of the block so that the valve block can be used in the reverse direction. It is desirable to provide it.

  In this case, the intended object of the present invention can be achieved by providing communication passages between the center bypass passage and the tank passage on both sides.

  An embodiment of the present invention will be described with reference to FIGS.

  In this embodiment, a case where a dual option valve device using two valve blocks is configured is taken as an example.

  As shown in FIG. 1, this optional valve device has a pump block 21 for introducing pressure oil from the hydraulic pump in order from the side closer to the hydraulic pump (upstream side) and the first optional device (hydraulic actuator). A total of three blocks, a first valve block 22a that controls the flow of pressure oil sent from the pump block 21 and a second valve block 22b that controls the flow of pressure oil, are joined to the second optional device. Is done.

  That is, this option valve device has a configuration in which the tank block 3 of the conventional option valve device having the same dual type shown in FIG. 6 is omitted.

  The basic configuration of each block 21, 22a, 22b is the same as the pump block 1 and the valve blocks 2a, 2b in the conventional apparatus shown in FIG. 6, and the pump block 21 includes a pressure oil passage 23 and a pressure oil passage 23. A branched center bypass passage 24 for bleed-off control and a tank passage 25 are provided, and a main relief valve 26 is provided in the tank passage 25.

  The first and second valve blocks 22a and 22b are connected to a pressure oil passage 27 communicating with the pressure oil passage 23 of the pump block 21, a center bypass passage 28, a tank passage 29, and a hydraulic actuator (not shown). Actuator passages 30 and 31 are provided, and a switching valve 32 is provided across the passages 27 to 31.

  In the case of this optional valve device, in both the first and second valve blocks 22a and 22b, communication passages 33 and 33 connecting the center bypass passages 28 and 28 and the tank passages 29 and 29 on the downstream side of the switching valves 32 and 32, respectively. Is provided.

  Of the communication passages 33, 33 of both the valve blocks 22a, 22b, the communication passage 33 of the first valve block 22a on the upstream side is blocked by a blocking plug 34 as an opening / closing means, and the second valve block 22b on the downstream side. The communication passage 33 is opened without a blocking plug.

  This will be described specifically and in detail with reference to FIGS.

  FIG. 2 shows a specific structure of the first valve block 22a, and FIG. 3 shows a specific structure of the second valve block 22b (the spool is not shown). 4 is an enlarged cross-sectional view taken along the line IV-IV in FIG. 2, and the upper side of the figure is the upstream side.

  The two valve blocks 22a and 22b are arranged symmetrically with respect to the block center so that two circuits of pressure oil, center bypass, and tanks 27, 28, and 29 are formed so that a circuit is formed even if the left and right directions are changed. Is provided. Reference numeral 35 denotes a spool hole in which a spool is provided.

  In this configuration, communication passages 33 and 33 are provided in a symmetrical arrangement between the center bypass passages 28 and 28 and the tank passages 29 and 29 on both sides.

  As for the first valve block 22a, as shown in FIG. 2, the blocking plugs 34, 34 are screwed into the openings 36, 36 opened on both sides of the block in order to process the both-side communication passages 33, 33. Thus, the both-side communication passages 33, 33 are blocked between the center bypass and the tank passages 28, 29, respectively.

  On the other hand, with respect to the second valve block 22b, the caps 37, 37 are attached to the openings 36, 36 in a state in which only the openings 36, 36 are closed instead of the blocking plugs 34, 34, so 33 and 33 are opened, that is, the center bypass and the tank passages 28 and 29 are in communication with each other.

  In this way, the center bypass passage 28 of the second valve block 22b in FIG. 1 communicates with the tank passage 29 on the downstream side of the switching valve 32, and this tank passage 29 is connected to the tank passage of the main valve device A. A hydraulic circuit capable of bleed-off control is configured as an entire optional valve device.

  In other words, in this optional valve device, the tank block is integrated with the valve blocks 22a and 22b, and the communication block 33 is provided in the valve blocks 22a and 22b as a substitute for the tank block, and the downstream side valve block (the first block) Only the communication passage 33 of the two-valve block) 22b is opened to establish a circuit.

  With this configuration, the tank block 3 in the conventional device of FIGS. 5 and 6 is omitted and the overall length L of the device is shortened while using the same configuration (common product) for both the first and second valve blocks 22a and 22b. Can do.

  For this reason, the space occupied by the optional valve device can be reduced, and the optional valve device can be easily incorporated even in a machine having a small valve installation space, such as a small hydraulic excavator.

  In addition, in order to obtain a bleed-off opening characteristic according to the spool stroke when taking a valve configuration in which a center bypass passage is provided in a symmetric arrangement, including a multiple type including the double type mentioned in this embodiment, It is desirable to connect the center bypass passages of adjacent valve blocks in a meandering manner.

  Also in this embodiment, from this point of view, both valve blocks 22a and 22b are connected to the center bypass passages 28 and 28 opposite to each other as shown in FIG. Is closed by plugs 38, 38, thereby forming a meandering flow path.

  By the way, in the above-described embodiment, the dual type option valve device provided with the two valve blocks 22a and 22b is taken as an example. However, the valve block can be added to constitute a triple or more option valve device.

  The present invention can also be applied to an optional valve device having only one valve block. Even in this case, as compared with the option valve device having a conventional three-block configuration, the point that the entire device can be made compact is the same as in the case of the multiple type.

  On the other hand, as the opening / closing means, a valve that opens and closes by an external operation may be used instead of the screw-in type blocking plug 34 described in the above embodiment.

1 is a hydraulic circuit diagram showing an optional valve device according to an embodiment of the present invention. It is sectional drawing which shows the specific structure of the 1st valve block in the same apparatus. It is sectional drawing which shows the specific structure of the 2nd valve block in the same apparatus. It is the IV-IV line expanded sectional view of FIG. It is a hydraulic circuit diagram which shows the option valve apparatus with the conventional valve block. It is a hydraulic circuit diagram in which the conventional valve block shows two optional valve devices.

Explanation of symbols

21 Pump block 22a First valve block on the upstream side 22b Second valve block on the downstream side 27 Pressure oil passage 28 Center bypass passage 29 Tank passage 32 Switching valve 33 Communication passage 34 Shut-off plug 36 Opening portion 37 Cap

Claims (5)

  In an optional valve device retrofitted to the main valve device to control the operation of the added hydraulic actuator, the pump block for introducing the pressure oil from the hydraulic pump and the flow of the pressure oil sent from the pump block are controlled. A valve block including a switching valve, and a pressure oil passage through which pressure oil passes, a center bypass passage for bleed-off control, a tank passage connected to a tank passage of the main valve device, An optional valve device comprising a communication passage for connecting a center bypass passage and a tank passage downstream of the switching valve, and an opening / closing means for opening / closing the communication passage.   2. The optional valve device according to claim 1, wherein a plurality of valve blocks are provided in a stacked manner in the flow direction of the pressure oil in a state where a plurality of valve blocks, each of the pressure oil, the center bypass, and the tank passages communicate with each other. An optional valve device characterized in that the communication passage is opened by the opening / closing means for the block, and the communication passage is blocked by the opening / closing means for the other valve blocks.   The optional valve device according to claim 1 or 2, wherein two center bypass passages and two tank passages of the valve block are provided symmetrically with respect to the block center, and between the center bypass passage and the tank passage on both sides. An optional valve device characterized in that a communication passage is provided for each.   The optional valve device according to any one of claims 1 to 3, wherein, as an opening / closing means, the communication passage is cut off from an outside in a state where the communication passage is blocked by an opening provided on a side surface of the valve block in order to process the communication passage. An optional valve device using a plug that is detachably screwed.   In a valve block of an optional valve device retrofitted to the main valve device, a pressure oil passage for passing pressure oil sent from the hydraulic pump through the pump block, a center bypass passage for bleed-off control, and a tank of the main valve device A tank passage connected to the passage, a switching valve for controlling the flow of pressure oil, a communication passage connecting the center bypass passage and the tank passage on the downstream side of the switching valve, and A valve block for an optional valve device, comprising opening / closing means for opening / closing the communication passage.

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