AU644984B1

AU644984B1 - Slide surface tight-coupling device for an S-shaped gate valve for concrete pumps

Info

Publication number: AU644984B1
Application number: AU41728/93A
Authority: AU
Inventors: Yoshiaki Inada; Toshio Takezaki
Original assignee: Mitsubishi Heavy Industries Ltd
Current assignee: Mitsubishi Heavy Industries Ltd
Priority date: 1992-07-10
Filing date: 1993-07-02
Publication date: 1993-12-23
Anticipated expiration: 2013-07-02
Also published as: JPH0626450A; CN1032710C; DE4322805A1; KR0146035B1; JP3145488B2; TW224503B; CN1086879A; KR940005366A; DE4322805C2

Description

-1- P/00/011 S4 Regulation 3.2

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT f Invention Title: SLIDE SURFACE TIGHT-COUPLING DEVICE FOR AN S-SHAPED GATE VALVE FOR CONCRETE

PUMPS

*e a o a a. a .&ta a a oaa a *r o r

S

*ta The following statement is a full description of this invention, including the best method of performing it known to us: GH&CO REF: P09991-EX:DAA:RK SLIDE SURFACE TIGHT-COUPLING DEVICE OF AN S-SHAPED GATE VALVE FOR CONCRETE PUMPS BACKGROUND OF THE INVENTION: Field of the Invention: i The present invention relates to a slide surface tight-coupling device of an S-shaped gate valve for concrete pumps.

Description of the Prior Art: '10 One example of a heretofore known concrete pmp having an S-shaped gate valve is illustrated in Figs, 2 through 6. Among these figures, Fig. 2 is a vertical crosssection view showing a concrete pump in the prior art; Fig.

3 is a vertical cross-section side view showing a pivotal coupling portion between a housing of the same concrete pump and a gate housing; Fig. 4 is a horizontal cross-section view taken along line X-X in Fig. 3 as viewed in the direction of arrows; Fig. 5 is a disintegrated side view showing a pivotal coupling portion on the side of the housing.of the same concrete pump; and Fig. 6 is a disintegrated side view showing a pivotal coupling portion on the side of the gate housing of the same concrete pump.

Now, a construction and an operation of the illustrated concrete pump in the prior art will be described with reference to Figs. 2 to 6. In Fig. 2, reference 1Anumerals 1 and 1' designate concrete cylinders, numerals 2 and 2' designate concrete pistons, numeral 4 in Figs. 2 to designates a housing on the side of the concrete cylinders 1 and and numeral 7 designates an abrasive resistant slide plate mounted to the same housing 4. Reference numeral 5 in Figs. 2 to 5 designates a gate housing, numeral 3 designates a, pivotal' coupling portion for pivotably coupling the same gate housing 5 to the above-mentioned housing 4, and this pivotal coupling portion 3 is constructed in the following manner. That is, the housing 4 and a hollow shaft 21 are fixed to each other by means of a keep plate 22, a bush 23 embedded in the gate housing 5 and the hollow shaft 21 on the side of the housing 4 are allowed to slide along slide surfaces a and b, and thereby the gate housing 5 is allowed to swing about a hinge, center B. Reference numeral designates a bolt-nut for fixing the opposite sides of the pivotal coupling portion 3 between the housing 4 and the gate housing Reference numeral 6 designates an S-shaped pipe, numeral 8 designates an abrasive-resistant slide ring mounted to a tip end portion of the same S-shaped pipe 6, reference numerals 9 and 10 designate bearings for supporting the same S-shaped pipe 6 within the gate housing so as to be swingable about.a swing center axis A, numeral 11 designates a pressing mechanism making use of a hydraulic -2pressure, numeral 12 designates a driving unit, numeral 13 designates a hopper, numeral 14 designates a drive liner, and provision is made such that the S-shaped pipe 6 can be made to swing about the above-mentioned swing center axis A via the dzrive unit 12 and the drive liner 14 to be alternately coupled to the concrete cylinders 1 and 1'.

,.In the heretofore known concrete pump shown in Figs. 2 to 6, when the concrete cylinder 1 and a concrete conveying pipe (not shown) have been connected via the Sshaped pipe 6, the piston 2 in the same concrete cylinder 1 is made to advance and concrete kept sucked withiA the concrete cylinder 1 is delivered to the concrete conveying pipe through the route of [concrete cylinder 1] [S-shaped pipe 6] [concrete conveying pipe], whereas the concrete .o 15 piston 2' in the concrete cylinder 1' is made to retreat and 004. 0 concrete is sucked through the route of [hopper 13] [concrete cylinder Alternatively, when the S-shaped pipe 6 has been switched and the concrete cylinder 1' and the concrete conveying pipe have been connected via the S-shaped pipe 6, the concrete piston 2' in the same concrete cylinder 1' is made to advance and concrete kept sucked within the concrete cylinder 1'.is delivered to the concrete conveying pipe through the route of [concrete cylinder [S-shaped pipe 6] [concrete conveying pipe], whereas the concrete 3 piston 2 in the concrete cylinder 1 is made to retreat and .concrete is sucked through the route of [hopper 13] [concrete cylinder 1].

When the concrete is delivered from the concrete cylinder It or 1' to the S-shaped pipe 6, leakage of the delivered concrete into the gate housing 5 is prevented by bringing the slide plate 7 on the side of the housing 4 and the slide ring 8 on the side of the S-shaped pipe 6 into tight contact. And in the event that the slide plate 7 and/or the slide ring 8 has been abraded, the pressing mechanism 11 making use of a hydraulic pressure is actuated to push the S-shaped pipe 6 towards the concrete cylinders 1 and 1' by the amount corresponding to the abrasion so that leakage of the delivered concrete into the gate housing may be consecutively prevented.

The above-described concrete pump in the prior art shown in Figs. 2 to 6 involved the following problems. That is, the S-shaped pipe 6 to be connected alternately to the concrete cylinders 1 and 1' necessitates, in view of its mechanism, to have a deviation between the swing center axis A and a center of the swing end (slide ring 8) of the Sshaped pipe 6 equal to a swing radius R as indicated in Fig. 2.

Accordingly, during the period when the S-shaped pipe 6 is receiving forced feed of concrete from the 4, concrete cylinder 1 or the S-shaped pipe 6 would be exerted a force F caused by the forced feeding pressure P at its opposite ends. Strictly speaking, the pressure P on the inlet side (on the side of the slide ring 8) of the S-shaped pipe 6 is !not equal to the pressure P on the outlet side, but the pressure on the outlet side is lower by the amount cbrresponding to a pressure loss within the S-shaped pipe 6 during the forced feeding. However, since the S-shaped pipe 6 is short the pressure loss is so small that it can be practically disregarded. In other words, the forces F acted upon the S-shaped pipe 6 at its opposite ends areinearly balancing, and owing to the pressing mechanism 11, the slide ring 8 is pressed against the slide plate 7 with an appropriate force.

5 However, a torque, that is, a moment of force M F x R caused by the deviation R of the center line of the Sshaped pipe 6 would act upon the S-shaped pipe 6, and consequently, the S-shaped pipe 6 supported swingably via the bearings 9 and 10 would be warped by a deflection angle a with respect to the swing center axis A.

This deflection angle a of the S-shaped pipe 6 would become unnegligible if the forced feeding pressure P becomes high, hence a gap clearance is produced between the slide plate 7 and the slide ring 8, and even if the S-shaped pipe 6 is pressed by means of the pressing mechanism 11, 5 i._ the gap clearance between the slide plate 7 and the slide ring 8 cannot be eliminated. Therefore, there was a problem that a paste component in concrete would leak out into the gate housing, resulting in degradation of a forced feeding performance.

SUMMARY OF THE INVENTION i It is an aim of the present invention to ameliorate 10 at least some of the problems of the prior art.

It is an advantage that the present invention a Sprovides a slide surface tight-coupling device of an Sshaped gate valve for concrete pumps which can improve a forced feeding performance and also can improve durabilities of a slide surface and a slide ring.

In a first aspect of the present invention, there is provided a concrete pump of the type that a slide plate is mounted to a housing on the side of concrete cylinders, a slide ring is mounted to an S-shaped pipe, the same S-shaped pipe is swingably supported from a gate housing, and the aforementioned housing and gate housing are coupled via a pivotal coupling portion, a hydraulic cylinder for adjusting an angle of contact between the above-mentioned slide plate and the above-mentioned slide ring is interposed between the above-described concrete cylinders and the 6 ai a. a 4 sa a 0Ota above-described gate housing.

According to the present invention, owing to the above-described structural feature of the slide surface tight-coupling device or an S-shaped gate valve for concrete pumps,.an angle of contact al between a slide plate and a slide ring is adjusted between zero and a certain angle depending',upon a deflection angle a 2 of an S-shaped pipe by controlling an operation'of a hydraulic cylinder to realize a 2 thus while the contact surfaces of the slide plate and the slide ring are held in parallel to each other, with the aid of the pressing action of a pressing mechanism making use of a hydraulic pressure, the slide plate and the slide ring are brought into tight contact with each other independently of the forced-feeding pressure, and thereby 15 leakage of a cement paste component in concrete into the gate housing can be prevented.

The features and advantages of the presen invention will become more apparent by reference to th following description of one preferred embodiment of th invention taken in conjunction with the accompanyin drawings.

BRIEF DESCRIPTION OF THE DRAWINGS: In the accompanying drawings: Fig. 1 is a vertical cross-section view showing -7t .e .e g one preferred embodiment of a slide surface tight-coupling device of an S-shaped gate valve for concrete pumps according to the present invention; Fig. 2 is a vertical cross-section view showing one example of an S-shaped valve of a concrete pump in the prior art; S.Fig. 3 is a vertical cross-section view showing a pivotal coupling portion between a housing of the same concrete pump and a gate housing; .0 Fig. 4 is a horizontal cross-section view taken along line X-X in Fig. 3 as viewed in the direction of arrows; Fig. 5 is a disintegrated side view showing "a pivotal coupling portion on the side of the housing of 15 the same concrete pump; and Fig. 6'is a disintegrated side view showing a pivotal coupling portion on the side of the gate housing of the same concrete pump.

DESCRIPTION OF THE PREFERRED EMBODIMENT: Now, the slide surface tight-coupling device of an S-shaped gate valve for concrete pumps according to the present, invention will be described in greater detail in connection to the preferred embodiment illustrated in Fig. 1. In Fig. 1, reference numerals 1 and 1' designate 8 i*0* concrete cylinders, numerals 2 and 2' designate concrete pistons, numeral 4 designates a housing on the side of the concrete cylinders 1 and and numeral 7 designates an abraveesve-resistant slide plate mounted to the same housing 4. Reference numeral 5 designates a gate housing, numeral 3 designates a pivotal coupling portion for pivotabling coipling the same gate housing 5 to the above-mentioned housing 4.

Reference numeral 6 designates an S-shaped pipe, numeral 8 designates an abrasive-resistant slide ring mounted to the tip end portion of the S-shaped pipe 6, numerals 9 and 10 designate bearings for supporting the same S-shaped pipe 6 so as to be swingable about a swiny center axis A within the gate housing 5, numeral 11 designates 15 a pressing mechanism making use of a hydraulic pressure, S numeral 12 designates a drive unit, numeral 13 designates a hopper, numeral 14 designates a drive liner, and the S arrangement is such that the S-shaped pipe 6 can be alternately connected to the concrete cylinders 1 and 1' by making the S-shaped pipe 6 swing about the swing center axis A via the drive unit 12 and the drive liner 14.

Reference numeral la designates a bracket on the side of the concrete cylinders 1 and numeral designates a bracket on the side of the above-described gate housing 5, numeral 16 designates a hydraulic cylinder for 0S0.

9004 On .4 04 040 9 adjusting an angle of contact between the above-mentioned slide plate 7 and the above-mentioned slide ring 8, and this hydraulic cylinder 16 is'interposed between the aforementioned blackets la and Sa.

Now an operation of the slide surface tightcoupling device of an S-shaped gate valve for concrete pumps illustrated in Fig'. 1 will be described in greater detail.

A moment of force M F x R caused by a deviation R of center axes of the S-shaped pipe 6 would act upon the o TO S-shaped pipe 6, resulting in warp of the S-shaped pipe 6 4*.

swingably supported via the bearings 9 and 10 by a deflection angle a 2 with respect to the swing center axis A.

This deflection angle a 2 would become unnegligible if the forced feeding pressure P becomes high, hence a gap clearance is produced between the slide plate 7 and the 446 slide ring 8, and even if the S-shaped pipe 6 is pressed by means of the pressing mechanism 11, the gap clearance S" between the slide plate 6 and the slide ring 8 cannot be eliminated.

At that moment, an angle of contact a 1 between the slide plate 7 and the slide ring 8 is adjusted between zero and a certain angle depending upon the deflection angle a 2 of the S-shaped pipe 6 by controlling the operation of the hydraulic cylinder 16 (See an adjusting distance 6 in Fig. 1) to realize a 1 a 2 in this way while the contact 10 surfaces of the slide plate 7 and the slide ring 8are held in parallel to each other, with the aid of the pressing action of the pressing mechanism 11 making use of a hydraulic pressure, the slide plate 7 and the slide ring 8 are brought into tight contact with each other independently of the forced-feeding pressure P, and thereby leakage of a cbment pas.te component in concrete into the gate housing can be prevented.

It is to be noted that it is possible to reserve the above-mentioned condition by manually changing the stroke of the hydraulic cylinder 16 in a stepwise:manner.

In addition, although the slide plate 7 and the slide ring 8 are brought into tight concact by manipulating the side of the slide ring 8 in the above-described embodiment, the slide plate 7 and the slide ring 8 could be brought into tight contact by manipulating the side of t-e slide plate 7.

As will be apparent from the detailed description of the preferred embodiment above, the slide surface tightcoupling device of an S-shaped gate valve cr concrete pumps according to the present invention can improve a forcedfeeding performance of a concrete pump and also can improve durabilities of a slide plate and a slide ring, because of the fact that an angle of contact a between a slide plate and a slide ring is adjusted between zero and a certain angle depending upon a deflection angle a2 of an S-shaped 11 pipe by controlling an oper on of a hydraulic cylinder to realize a 2, thus while the contact surfaces of the slide plate and the slide ring are brought into tight contact with each other endependently of the forced-feeding pressure, land thereby leakage of a cement paste component in concrete into the gate housing can be prevented.

S.While a principle of the present invention S has been described above in connection to one preferred embodiment of the invention, it is intended that all matter 6o contained in the above description and illustrated in the accompanying drawings shall be interpreted to:be illustrative and not as limitation to the scope of the invention.

6 *o oroo .9 o -12

Claims

4. A slide surface tight-coupling device of an S-shaped gate valve for a concrete pump substantially as herein described with reference to figure 1 of the accompanying drawings. Dated this 2nd day of July 1993 MITSUBISHI JUKOGYO KABUSHIKI KAISHA By their Patent Attorney GRIFFITH HACK CO. *0 &i SO *O S *5* S S *0 0 no, OOSS 14