US20140306488A1

US20140306488A1 - Pilot Valve Attachment Structure of Construction Machine

Info

Publication number: US20140306488A1
Application number: US14/360,950
Authority: US
Inventors: Tomoyuki Tanaka; Hiroshi Tabeta
Original assignee: Hitachi Construction Machinery Co Ltd
Current assignee: Hitachi Construction Machinery Co Ltd
Priority date: 2011-12-21
Filing date: 2012-10-02
Publication date: 2014-10-16
Also published as: KR20140113670A; CN104011299A; WO2013094277A1; EP2796622A1; JP2013129996A

Abstract

Provided is a pilot valve attachment structure of a construction machine which can reduce an oppressive sensation that an operator sitting on an operator's seat may feel. The present invention is provided in a compact excavator having a travel operation device 11 including a pilot valve 18, and configured such that the pilot valve 18 is attached to a floor plate 15, wherein a recessed part 20 having a hole 20 b, into which a casing 18 a forming an outer frame of the pilot valve 18 can be inserted, on a bottom part 20 a thereof is provided on the floor plate 15, the casing 18 a of the pilot valve 18 is attached to the bottom part 20 a of the recessed part 20 in a state where the casing 18 a of the pilot valve 18 is inserted into the hole 20 b of the recessed part 20, and a mat shaped seal member 21 for sealing a space that is formed around the casing 18 a of the pilot valve 18 when the casing 18 a is inserted into the hole 20 b of the recessed part 20.

Description

TECHNICAL FIELD

The present invention relates to a pilot valve attachment structure of a construction machine, which is provided in a construction machine such as a compact excavator and is configured such that a pilot valve included in a travel operation device arranged in front of an operator's seat is attached to a floor plate.

BACKGROUND ART

Regarding the techniques above, JP 2011-64064 A (Patent document 1) describes the prior arts. The techniques disclosed in Patent document 1 relates to a structure in which a pilot valve included in a travel operation device provided in an excavator having an travel base, a upperstructure, and a working device is attached to a flat-shaped floor of an operator's seat, that is, a floor plate.

PRIOR ART DOCUMENT

Patent Document

Patent Document 1: Japanese Patent Application Laid-Open No. 2011-64064 A

SUMMARY

Problems to be Solved by the Invention

In the conventional techniques according to Patent document 1 described above, because the pilot valve is attached to the flat-shaped floor plate, a height dimension of a part of the pilot valve which projects upwardly from the floor plate becomes large. As a result of this, an operation space for the travel operation device arranged in front of the operator's seat tends to become small, and accordingly, an operator sitting on the operator's seat is likely to feel an oppressive sensation. They are especially disadvantageous when a construction machine provided with the pilot valve according to the conventional techniques is a small machine such as a small excavator where the size of an operation space of a travel operation device tends to be limited in its manufacture.
The present invention was made in view of such problems stemming from the conventional techniques described above, and an object of the present invention is to provide a pilot valve attachment structure of a construction machine which can reduce an oppressive sensation that an operator sitting on an operator's seat is likely to feel.

Means for Solving the problem

In order to achieve the object described above, the present invention provides a pilot valve attachment structure of a construction machine that includes a travel base, a upperstructure arranged on the travel base, a working device attached to the upperstructure, an operator's seat arranged on a floor plate that is formed on the upperstructure, and a travel operation device arranged in front of the operator's seat and having a pilot valve, the pilot valve included in the travel operation device being attached to the floor plate, wherein a recessed part having a hole, into which a casing forming an outer frame of the pilot valve can be inserted, on a bottom part thereof is provided on the floor plate, the casing of the pilot valve is attached to the bottom part of the recessed part in a state where the casing of the pilot valve is inserted into the hole of the recessed part, and a mat shaped seal member for sealing a space that is formed around the casing of the pilot valve when the casing is inserted into the hole of the recessed part.
The present invention is configured such that the casing of the pilot valve is attached on the bottom part of the recessed part of the floor plate, and accordingly, the casing of the pilot valve can be attached to the floor plate such that the top surface of the pilot valve projecting from the top surface of the floor plate is low. Because the recessed part is formed in the floor plate, there is concern that contaminants, such as mud or muddy water, may enter the inside of the pilot valve through the recessed part, however, the mat shaped seal member that seals a space formed around the casing of the pilot valve can prevent the contaminants such as mud or muddy water from entering the inside of the pilot valve.
Furthermore, according to the present invention, the mat shaped seal member is made of a rubber member. With this configuration, the mat shaped seal member can be bended due to elasticity and is easily attached to or removed from the recessed part of the floor plate.
Furthermore, according to the present invention, the mat shaped seal member consists of a first divided member and a second divided member that are dividedly formed so as to interpose the casing of the pilot valve therebetween. With this configuration, because the mat shaped seal member is dividedly formed into the first divided member and the second divided member so as to be separated with each other, an operation for disposing the mat shaped seal member around the casing of the pilot valve can be easily performed.
Furthermore, according to the present invention, the mat shaped seal member includes a projection part on a lower side thereof, and a hole part into which the projection part is inserted is formed on the bottom part of the recessed part. With this configuration, because the projection part of the mat shaped seal member is inserted into the hole part of the floor plate, it is possible to easily position the mat shaped seal member within the recessed part and to stably hold the mat shaped seal member which is attached to the recessed part of the floor plate, without causing any positional deviation with respect to the recessed part.
Furthermore, according to the present invention, the mat shaped seal member is attached to the recessed part so that a top surface of the mat shaped seal member forms approximately the same plane as a top surface of the floor plate and the top surface of the mat shaped seal member becomes in the height equal to or higher than that of the floor plate. With this configuration, because the mat shaped seal member is attached to the recessed part such that the top surface of the mat shaped seal member forms approximately the same plane as that of the floor plate and the top surface of the mat shaped seal member becomes in the height equal to or higher than that of the floor plate, contaminants such as mud or muddy water hardly enter the recessed part, and thus it is possible to certainly prevent the contaminants from entering the inside of the pilot valve.

Effect of the Invention

The present invention is configured such that a pilot vale is attached to a recessed part formed in a floor plate, and accordingly, a part of the pilot valve projecting from the floor plate can be made lower than that of a conventional structure. With this configuration, an oppressive sensation that an operator sitting on the operator's seat is likely to feel in a limited narrow operation space can be reduced, and it is possible to secure a comfortable operability more than before. Furthermore, because a mat shaped seal member seals a space formed around the pilot valve, it is possible to prevent contaminants such as mud or muddy water from entering the inside of the pilot valve, and thus it is possible to realize to maintain good performance of the pilot valve as well as to secure excellent durability thereof.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a side view of a compact excavator illustrated as an example of a construction machine provided with an embodiment of a pilot valve attachment structure according to the present invention.

FIG. 2 is a perspective view of an arrangement part of an operator's seat provided in the compact excavator illustrated in FIG. 1.

FIG. 3 is an enlarged perspective view of a main part where an operation pedal, etc is removed from a state illustrated in FIG. 2.

FIG. 4 is a perspective view of a part of FIG. 3, which is illustrated from another angle.

FIG. 5 illustrates relationship of stepping-on action of an operation pedal and the height of a casing of a pilot valve.

FIG. 6 illustrates a mat shaped seal member provided in the present embodiment, in particular, FIG. 6( a) is a perspective view illustrated from a front side, and FIG. 6( b) is a perspective view illustrated from a back side.

FIG. 7 illustrates relationship of attachment between a mat shaped seal member provided in the present embodiment and a floor plate, in particular, FIG. 7( a) is a perspective view of a state before the mat shaped seal member is attached to the floor plate, and FIG. 7 (b) is a perspective view of a state in which the mat shaped seal member is attached to the floor plate.

FIG. 8 is a perspective view of a state where a mat shaped seal member is removed from a state illustrated in FIG. 4.

FIG. 9 is a plan view of a part of a floor plate where a mat shaped seal member provided in the present embodiment is removed.

FIG. 10 is an enlarged view of a cross section A of FIG. 9.

FIG. 11 is an enlarged view of a cross section B of FIG. 9.

FIG. 12 is a cross sectional view of a main part side where a mat shaped seal member according to the present embodiment is attached in a state illustrated in FIG. 10.

DESCRIPTION OF EMBODIMENTS

Hereinafter, an embodiment of a pilot valve attachment structure of a construction machine according to the present invention will be described with reference to the drawings.
A construction machine provided with a pilot valve attachment structure according to the present invention, for example, constitutes a small sized machine and is a compact excavator whose operation space of an operation device to be arranged in an operator's cab is relatively narrow. As illustrated in FIG. 1, the compact excavator includes a travel base 1, an upperstructure 2 that is arranged on the travel base 1, and a working device 3 that is attached to the upperstructure 2 with being rotatable in a vertical direction. The working device 3 includes a boom 4 to be attached to the upperstructure 2, an arm 5 to be attached to a tip of the boom 4, and a bucket 6 to be attached to a tip of the arm 5. The upperstructure 2 is provided with an operator's cab 7 and a counterweight 8 for securing weight balance. A machine room 9 in which an engine, a hydraulic pump, etc., are accommodated is arranged between the operator's cab 7 and the counterweight 8. In the operator's cab 7, an operator's seat 10 on which an operator sits is arranged, and as illustrated in FIG. 2, a travel operation device 11 including an operation lever 16, an operation pedal 17, and a pilot valve 18 for traveling is arranged in front of the operator's seat 10. Work operation devices 10 a, 10 b are arranged respectively on both sides of the operator's seat 10.
As illustrated in FIGS. 7 to 11, the pilot valve attachment structure of a construction machine according to the present embodiment includes a floor plate 15 of the operator's cab 7 which is provided with a recessed part 20. On a bottom part 20 a of the recessed part 20, a hole 20 b into which a casing 18 a forming an outer frame of the pilot valve 18 can be inserted is provided. As illustrated in FIGS. 10 and 11, the casing 18 a of the pilot valve 18 is attached to the bottom part 20 a of the recessed part 20 in a state where the casing 18 a of the pilot valve 18 is inserted into the hole 20 b of the recessed part 20.
As illustrated in FIGS. 3 to 5 and 12, the present embodiment includes a mat shaped seal member 21 for sealing a space that is formed around the casing 18 a of the pilot valve 18 when the casing 18 a is inserted into the hole 20 b of the recessed part 20. For example, the mat shaped seal member 21 is made of a rubber member, and as illustrated in FIGS. 4 and 6, consists of a first divided member 21 a and a second divided member 21 b that are dividedly formed so as to interpose the casing 18 a of the pilot valve 18 therebetween.
As illustrated in FIGS. 6( b) and 7, the mat shaped seal member 21 includes a projection part 22 on a lower side thereof. On the bottom part 20 a of the recessed part 20, a hole part 23 into which the projection part 22 is inserted is provided. Furthermore, as illustrated in FIG. 5, the mat shaped seal member 21 is attached to the recessed part 20 so that a top surface of the mat shaped seal member 21 forms approximately the same plane as a top surface of the floor plate 15 and the top surface of the mat shaped seal member 21 becomes in the height equal to or higher than that of the floor plate 15.
As illustrated in FIG. 5, a mounting height of the pilot valve 18 to be attached to the recessed part 20 of the floor plate 15 is set such that a height position from the floor plate 15 to a top surface of the casing 18 a of the pilot valve 18 is to be a relatively low height position H that is within a range where the floor plate 15 is not contact with the heel 30 a of a shoe 30 of an operator when the operator sitting on the operator's seat 10 steps on the operation pedal 17. For example, the height position H is set to be about 20 mm.
In the compact excavator provided with the pilot valve attachment structure according to the present embodiment, when an operator sitting on the operator's seat 10 operates the work operation devices 10 a, 10 b that are illustrated in FIG. 2, the upperstructure 2 revolves or the working device 3 rotates in a vertical direction to perform such as digging work of earth and sand via the bucket 6. Furthermore, when an operator sitting on the operator's seat 10 operates the operation lever 16 of the travel operation device 11 or steps on the operation pedal 17, the pilot valve 18 activates and a travel directional control valve (not shown) is switched. Accordingly, pressure oil is supplied from a hydraulic pump accommodated in the machine room 9 to left and right motors via the travel directional control valve so that the travel base 1 can travel.
In the pilot valve attachment structure according to the present embodiment configured as above, because the casing 18 a of the pilot valve 18 is attached to the bottom part 20 a of the recessed part 20 of the floor plate 15, the casing 18 a of the pilot valve 18 can be attached to the floor plate 15 such that the top surface of the pilot valve 18 projecting from the top surface of the floor plate 15 is low. With this configuration, an oppressive sensation that an operator sitting on the operator's seat 10 is likely to feel in a limited narrow operation space can be reduced, and it is possible to secure a comfortable operability.
Because the recessed part 20 is formed in the floor plate 15, there is concern that contaminants, such as mud attached to shoes of an operator or muddy water generated at the time of washing the mud, may enter the inside of the pilot valve 18 through the recessed part 20, however, the mat shaped seal member 21 that seals a space formed around the casing 18 a of the pilot valve 18 can prevent the contaminants such as mud or muddy water from entering the inside of the pilot valve 18.
Furthermore, in the present embodiment, because the mat shaped seal member 21 is made of a rubber member, the mat shaped seal member 21 can be bended due to elasticity and is easily attached to or removed from the recessed part 20 of the floor plate 15.
Still further, in the present embodiment, because the mat shaped seal member 21 is dividedly formed into the first divided member 21 a and the second divided member 21 b so as to be separated with each other, an operation for disposing the mat shaped seal member 21 around the casing 18 a of the pilot valve 18 can be easily performed.
Still further, in the present embodiment, because the projection part 22 of the mat shaped seal member 21 is inserted into the hole part 23 of the floor plate 15, it is possible to easily position the mat shaped seal member 21 within the recessed part 20 and to stably hold the mat shaped seal member 21 which is attached to the recessed part 20 of the floor plate 15, without causing any positional deviation with respect to the recessed part 20.
Still further, in the present embodiment, because the mat shaped seal member 21 is attached to the recessed part 20 such that the top surface of the mat shaped seal member 21 forms approximately the same plane as that of the floor plate 15 and the top surface of the mat shaped seal member 21 becomes in the height equal to or higher than that of the floor plate 15, contaminants such as mud or muddy water hardly enter the recessed part 20, and thus it is possible to certainly prevent the contaminants from entering the inside of the pilot valve 18.

EXPLANATION OF REFERENCES

1 travel base
2 upperstructure
3 working device
10 operator's seat
11 travel operation device
15 floor plate
18 pilot valve
18 a casing
20 recessed part
20 a bottom part
20 b hole
21 mat shaped seal member
21 a first divided member
21 b second divided member
21 c hole
22 projection part
23 hole part

Claims

1. A pilot valve attachment structure of a construction machine that includes a travel base, an upperstructure arranged on the travel base, a working device attached to the upperstructure, an operator's seat arranged on a floor plate that is formed on the upperstructure, and a travel operation device arranged in front of the operator's seat and having a pilot valve, the pilot valve included in the travel operation device being attached to the floor plate, wherein

a recessed part having a hole, into which a casing forming an outer frame of the pilot valve can be inserted, on a bottom part thereof is provided on the floor plate,

the casing of the pilot valve is attached to the bottom part of the recessed part in a state where the casing of the pilot valve is inserted into the hole of the recessed part, and

a mat shaped seal member for sealing a space that is formed around the casing of the pilot valve when the casing is inserted into the hole of the recessed part.

2. The pilot valve attachment structure of a construction machine according to claim 1, wherein

the mat shaped seal member is made of a rubber member.

3. The pilot valve attachment structure of a construction machine according to claim 2, wherein

the mat shaped seal member consists of a first divided member and a second divided member that are dividedly formed so as to interpose the casing of the pilot valve therebetween.

4. The pilot valve attachment structure of a construction machine according to claim 3, wherein

the mat shaped seal member includes a projection part on a lower side thereof, and

a hole part into which the projection part is inserted is formed on the bottom part of the recessed part.

5. The pilot valve attachment structure of a construction machine according to claim 4, wherein

the mat shaped seal member is attached to the recessed part so that a top surface of the mat shaped seal member forms approximately the same plane as a top surface of the floor plate and the top surface of mat shaped seal member becomes in the height equal to or higher than that of the floor plate.