CN205099287U - Drive attitude throttle speed adjust loop's fork truck hydraulic system - Google Patents
Drive attitude throttle speed adjust loop's fork truck hydraulic system Download PDFInfo
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- CN205099287U CN205099287U CN201520890382.XU CN201520890382U CN205099287U CN 205099287 U CN205099287 U CN 205099287U CN 201520890382 U CN201520890382 U CN 201520890382U CN 205099287 U CN205099287 U CN 205099287U
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Abstract
The utility model discloses a drive attitude throttle speed adjust loop's fork truck hydraulic system, including multiple directional control valve, oil inlet P, oil return opening T and surge valve, the oil inlet C of multiple directional control valve and the oil inlet of surge valve communicate oil inlet P respectively, and the oil return opening D of multiple directional control valve and the oil -out of surge valve communicate oil return opening T respectively, when the multiple directional control valve commutates to first work position, its actuator port F intercommunication its oil inlet C and oil -out E, its oil return opening of the 2nd actuator port G intercommunication D, when the multiple directional control valve commutates to second work position, its oil return opening of actuator port F intercommunication D, the 2nd actuator port G intercommunication its oil inlet C and oil -out E, the control port that has an one end place of spring of the oil -out E of multiple directional control valve intercommunication surge valve, the control port intercommunication oil inlet P at the one end place of spring is not taken to the surge valve. The utility model discloses can guarantee that fork truck has invariable portal slope and accessory speed of action in unloaded or area when carrying, guaranteed work efficiency.
Description
Technical field
The utility model relates to a kind of forklift hydraulic system, particularly relates to a kind of forklift hydraulic system with dynamic throttling speed control circuit.
Background technology
At present, what the fork truck of domestic below 25T great majority adopted is hydraulic system with constant displacement pump, the flow of system be generally rise according to door frame needed for traffic requirement determine.And when door frame do or accessory action time, due to the requirement of operating cylinder kinematic velocity, required flow is only 30% ~ 50% of maximum flow, unnecessary flow returns in hydraulic reservoir by by pass valve high pressure kicks, thereby produce very large degradation of energy, system is caused to generate heat, the normal work of influential system.
Chinese Patent Application No. is that the utility application of CN201410224032.X proposes a kind of forklift hydraulic system with other oil circuit throttling speed control circuit, it is built in bypass throttling oil duct in multiple directional control valve, regulate the flow entering operating cylinder, the flow avoiding system unnecessary returns in hydraulic reservoir by by pass valve high pressure kicks, reduces system heating.But, the program also exists following not enough simultaneously: under the prerequisite that revolution speed is certain, the program leans forward when bringing onto load can be faster than the speed that leans forward during zero load, and when bringing onto load, hypsokinesis then can be slower than hypsokinesis speed during zero load, can affect the normal work efficiency of fork truck thus.Therefore, this scheme still cannot realize dynamic throttling speed governing, no matter under failing to realize forklift door frame or the whether load-carrying situation of accessory, and the feature that the speed of its action is all constant.
Utility model content
The utility model provides a kind of forklift hydraulic system with dynamic throttling speed control circuit, which overcomes the weak point existing for forklift hydraulic system of prior art.
The utility model solves the technical scheme that its technical matters adopts: a kind of forklift hydraulic system with dynamic throttling speed control circuit, comprises multiple directional control valve, oil inlet P and oil return inlet T; Also comprise throttle compensating valve, multiple directional control valve at least has oil inlet C, return opening D, oil outlet E, the first actuator port F and the second actuator port G, the oil inlet C of this multiple directional control valve is communicated with oil inlet P respectively with the oil inlet of throttle compensating valve, and the return opening D of multiple directional control valve is communicated with oil return inlet T respectively with the oil outlet of throttle compensating valve; When multiple directional control valve commutation is to the first working position, its first actuator port F is communicated with its oil inlet C and oil outlet E, and its second actuator port G is communicated with its return opening D; When multiple directional control valve commutation is to the second working position, its first actuator port F is communicated with its return opening D, and its second actuator port G is communicated with its oil inlet C and oil outlet E; The oil outlet E of multiple directional control valve is communicated with the control port at the place, one end with spring of throttle compensating valve, and the control port at one end place of throttle compensating valve not with spring is communicated with oil inlet P.
Further, also comprise by pass valve, the oil inlet of this by pass valve is communicated with described oil inlet P with control port, and the oil outlet of this by pass valve is communicated with described oil return inlet T.
Further, described multiple directional control valve, throttle compensating valve are integrated in a body, this body is provided with described oil inlet P, oil return inlet T, and the first pressure oil port A and the second pressure oil port B, first pressure oil port A is communicated with described first actuator port F, and the second pressure oil port B is communicated with described second actuator port G.
Further, described multiple directional control valve, throttle compensating valve, by pass valve are integrated in a body, this body is provided with described oil inlet P, oil return inlet T, and the first pressure oil port A and the second pressure oil port B, first pressure oil port A is communicated with described first actuator port F, and the second pressure oil port B is communicated with described second actuator port G.
Further, the spring pre-tightening compressive force of described throttle compensating valve is adjustable.
Further, when described multiple directional control valve commutation is to the first working position, its first actuator port F adopts throttling passage to be communicated with oil inlet C; When multiple directional control valve commutation is to the second working position, its second actuator port G adopts throttling passage to be communicated with oil inlet C.
Further, the first actuator port F of described multiple directional control valve is communicated with the rodless cavity hydraulic fluid port A of the operating cylinder of fork truck
t/c, the second actuator port G is communicated with the rod chamber hydraulic fluid port B of the operating cylinder of fork truck
t/c.
Further, described first pressure oil port A is communicated with the rodless cavity hydraulic fluid port A of the operating cylinder of fork truck
t/c, the second pressure oil port B is communicated with the rod chamber hydraulic fluid port B of the operating cylinder of fork truck
t/c.
Further, described multiple directional control valve is 3 position-5 way valve.
Compared to prior art, the utility model has following beneficial effect:
1, throttle compensating valve set by the utility model coordinates multiple directional control valve, can according to fluid uninterrupted regulating spool aperture size, and when fluid flow is determined, the spool aperture size of throttle compensating valve is determined, the flow flowing back to hydraulic reservoir through throttle compensating valve is determined, the demand of constant flow when forklift door frame inclination or accessory action can be met, the i.e. constant airspeed of door frame inclination and accessory action, ensure that fork truck has constant door frame when zero load or band are carried and tilts and accessory responsiveness, thus make the speed of door frame inclination and accessory be unlikely to cause speed too low because of load too low, be unlikely to cause speed to change because of load variations, ensure that work efficiency, and avoid the door frame that causes because load is excessive tilt and the responsiveness of accessory too fast and there is fork truck potential safety hazard,
2, the utility model is as further improvement: when multiple directional control valve commutation is to the first working position, its first actuator port F adopts throttling passage to be communicated with oil inlet C, when multiple directional control valve commutation is to the second working position, its second actuator port G adopts throttling passage to be communicated with oil inlet C, this improvement can regulate the flow entering operating cylinder, the flow avoiding system unnecessary returns in hydraulic reservoir by by pass valve high pressure kicks, reduces system heating;
3, the utility model is as further improvement: the spring pre-tightening compressive force of throttle compensating valve is adjustable, and this improvement makes the inclination of forklift door frame and accessory moving velocity all can adjust according to actual needs, simple to operation.
Below in conjunction with drawings and Examples, the utility model is described in further detail; But a kind of forklift hydraulic system with dynamic throttling speed control circuit of the present utility model is not limited to embodiment.
Accompanying drawing explanation
Fig. 1 is that the utility model is in the hydraulic schematic diagram of inoperative position at multiple directional control valve;
Fig. 2 is that the utility model is in the hydraulic schematic diagram of the first working position at multiple directional control valve;
Fig. 3 is the stressed schematic diagram of throttle compensating valve of the present utility model.
Fig. 4 is that the utility model is in the hydraulic schematic diagram of the second working position at multiple directional control valve.
Detailed description of the invention
Embodiment, shown in Figure 1, a kind of forklift hydraulic system with dynamic throttling speed control circuit of the present utility model, comprises multiple directional control valve 4, oil inlet P, oil return inlet T and throttle compensating valve 6.Multiple directional control valve 4 at least has oil inlet C, return opening D, the first actuator port F, the second actuator port G and oil outlet E, in the present embodiment, this multiple directional control valve 4 is specially 3 position-5 way valve, the oil inlet C of this multiple directional control valve 4 is communicated with oil inlet P respectively with the oil inlet of throttle compensating valve 6, the return opening D of multiple directional control valve 4 is communicated with oil return inlet T respectively with the oil outlet of throttle compensating valve 6, specifically, the return opening D of multiple directional control valve 4, the oil outlet of throttle compensating valve 6 adopt back oil road 7 to be communicated with oil return inlet T.When multiple directional control valve 4 commutates to the first working position, its first actuator port F is communicated with oil inlet C and oil outlet E, and the second actuator port G is communicated with return opening D; When multiple directional control valve 4 commutates to the second working position, its first actuator port F is communicated with return opening D, and the second actuator port G is communicated with oil inlet C and oil outlet E.The oil outlet E of multiple directional control valve 4 is communicated with the control port at the place, one end with spring of throttle compensating valve 6, and the control port at one end place of throttle compensating valve 6 not with spring is communicated with oil inlet P.
During use, the first actuator port F of described multiple directional control valve 4 is communicated with the rodless cavity hydraulic fluid port A of the operating cylinder 1 of fork truck
t/c, the second actuator port G is communicated with the rod chamber hydraulic fluid port B of the operating cylinder 1 of fork truck
t/c.This operating cylinder 1 is the dump ram of forklift door frame.
In the present embodiment, the utility model also comprises by pass valve 3, and the oil inlet of this by pass valve 3 is communicated with described oil inlet P with control port, and the oil outlet of this by pass valve 3 is communicated with described oil return inlet T.This by pass valve 3 does safety valve and uses, and when normally working, this by pass valve 3 is in closed condition.
In the present embodiment, described multiple directional control valve 4, throttle compensating valve 6, by pass valve 3 are integrated in a body 2, this body 2 is provided with described oil inlet P, oil return inlet T, and the first pressure oil port A and the second pressure oil port B, the first pressure oil port A is communicated with the rodless cavity hydraulic fluid port A of described first actuator port F and operating cylinder 1
t/c, the second pressure oil port B is communicated with the rod chamber hydraulic fluid port B of described second actuator port G and operating cylinder 1
t/c.
In the present embodiment, the spring pre-tightening compressive force of described throttle compensating valve 6 is adjustable, the fluid applied pressure value of being opened by the initial pre compressed magnitude adjustable throttle compensating valve spool changing spring.
In the present embodiment, when described multiple directional control valve 4 commutates to the first working position, its first actuator port F adopts throttling passage 8 to be communicated with oil inlet C, and when multiple directional control valve 4 commutates to the second working position, its second actuator port G adopts throttling passage 5 to be communicated with oil inlet C.This throttling passage 5,8 is respectively cutoff port or throttling channel.
When multiple directional control valve 4 is in inoperative position (i.e. meta), as shown in Figure 1, first actuator port F of multiple directional control valve 4 is not all communicated with oil inlet C with the second actuator port G, all be not communicated with return opening D, the oil outlet E of multiple directional control valve 4 is not communicated with its first actuator port F and the second actuator port G yet.
When forklift door frame leans forward work, multiple directional control valve 4 commutates to the first working position (i.e. right position), as shown in Figure 2, now, first actuator port F of multiple directional control valve 4 is communicated with oil inlet C and oil outlet E, second actuator port G is communicated with return opening D, and the hydraulic oil of fork truck enters from the oil outlet of gear type pump through oil inlet P, by way of the first oil inlet C of multiway valve 4, the first actuator port F, the first pressure oil port A to the rodless cavity hydraulic fluid port A of operating cylinder
t/c, oil return liquid is then through the rod chamber hydraulic fluid port B of operating cylinder
t/c, the second pressure oil port B, the second actuator port G of multiple directional control valve 4, return opening D, back oil road 7, oil return inlet T flow back to hydraulic reservoir.
Act on the oil liquid pressure of throttle compensating valve 6 not with spring one end (namely this oil liquid pressure refers to the pressure of fluid) and be designated as P
p, depend on the input pressure of oil inlet P, when the rotating speed of gear type pump improves, the flow of fluid increases, P
palso increase thereupon; Act on the fluid of throttle compensating valve 6 with spring one end to be drawn by the oil outlet E of multiple directional control valve 4, its oil liquid pressure is designated as P
e, because oil outlet E is communicated with by the internal galleries of multiple directional control valve 4 with the first actuator port F, therefore, have P
e≈ P
f, P
f=P
aT/C=load oil pressure, P
ffor the oil liquid pressure of the first actuator port F of multiple directional control valve 4, P
aT/Cfor the rodless cavity hydraulic fluid port A of operating cylinder
t/coil liquid pressure, depend on fork truck load.Therefore, for throttle compensating valve 4 spool force analysis as shown in Figure 3, F
pPbe designated as oil liquid pressure P
pcaused application force, F
pP=P
pxA
pP, A
pPfor oil liquid pressure P
pactive area, F
pEbe designated as oil liquid pressure P
ecaused application force, F
pE=P
exA
pE, A
pEfor oil liquid pressure P
eactive area, F is designated as the application force of spring to the spool of throttle compensating valve 4, F=K △ x, and wherein K is the stiffness factor of spring, and △ x is the amount of compression of spring.For a product, once design typification, then A
pP, A
pEand K is the constant of known determination.Therefore, for the spool of throttle compensating valve 4, when its stress balance, there is F
pP=F
pE+ F, then the aperture of spool is certain, and the flow that the hydraulic oil of being come in by oil inlet P flows back to hydraulic reservoir from throttle compensating valve 6 through back oil road 7 is certain.Work as F
pP>F
pEduring+F, then spool moves right, and make its aperture become large, the flow that the hydraulic oil of being come in by oil inlet P flows back to fuel tank from throttle compensating valve 6 through back oil road 7 increases; Work as F
pP<F
pE+ F, then spool is moved to the left, and its aperture is diminished, and the flow that the pressure oil of being come in by oil inlet P flows back to hydraulic reservoir from throttle compensating valve 4 through back oil road 7 reduces.
When forklift door frame hypsokinesis works, multiple directional control valve 4 commutates to the second working position (i.e. left position), as shown in Figure 4, now, first actuator port F of multiple directional control valve 4 is communicated with return opening D, second actuator port G is communicated with oil inlet C and oil outlet E, and the hydraulic oil of fork truck enters from the oil outlet of gear type pump through oil inlet P, by way of the first oil inlet C of multiway valve 4, the second actuator port G, the second pressure oil port B to the rod chamber hydraulic fluid port B of operating cylinder
t/c, oil return liquid is then through the rodless cavity hydraulic fluid port A of operating cylinder
t/c, the first pressure oil port A, the first actuator port F of multiple directional control valve 4, return opening D, back oil road 7, oil return inlet T flow back to hydraulic reservoir.
Act on the oil liquid pressure of throttle compensating valve 6 not with spring one end (namely this oil liquid pressure refers to the pressure of fluid) and be designated as P
p, depend on the input pressure of oil inlet P, when the rotating speed of gear type pump improves, the flow of fluid increases, P
palso increase thereupon; Act on the fluid of throttle compensating valve 6 with spring one end to be drawn by the oil outlet E of multiple directional control valve 4, its oil liquid pressure is designated as P
e, because oil outlet E is communicated with by the internal galleries of multiple directional control valve 4 with the second actuator port G, therefore, have P
e≈ P
g, P
g=P
bT/C=load oil pressure, P
gfor the oil liquid pressure of the second actuator port G of multiple directional control valve 4, P
bT/Cfor the rod chamber hydraulic fluid port B of operating cylinder
t/coil liquid pressure, depend on fork truck load.Therefore, for throttle compensating valve 4 spool force analysis as shown in Figure 3, F
pPbe designated as oil liquid pressure P
pcaused application force, F
pP=P
pxA
pP, A
pPfor oil liquid pressure P
pactive area, F
pEbe designated as oil liquid pressure P
ecaused application force, F
pE=P
exA
pE, A
pEfor oil liquid pressure P
eactive area, F is designated as the application force of spring to the spool of throttle compensating valve 4, F=K △ x, and wherein K is the stiffness factor of spring, and △ x is the amount of compression of spring.For a product, once design typification, then A
pP, A
pEand K is the constant of known determination.Therefore, for the spool of throttle compensating valve 4, when its stress balance, there is F
pP=F
pE+ F, then the aperture of spool is certain, and the flow that the hydraulic oil of being come in by oil inlet P flows back to hydraulic reservoir from throttle compensating valve 6 through back oil road 7 is certain.Work as F
pP>F
pEduring+F, then spool moves right, and make its aperture become large, the flow that the hydraulic oil of being come in by oil inlet P flows back to fuel tank from throttle compensating valve 6 through back oil road 7 increases; Work as F
pP<F
pE+ F, then spool is moved to the left, and its aperture is diminished, and the flow that the pressure oil of being come in by oil inlet P flows back to hydraulic reservoir from throttle compensating valve 4 through back oil road 7 reduces.
In sum, when load is certain, P
enecessarily, along with the rotating speed of gear type pump increases, fluid flow increases, P
palso increase, therefore, the spool aperture of throttle compensating valve 4 increases, and unnecessary fluid flow flows back to hydraulic reservoir through throttle compensating valve 4 and back oil road 7; When load is certain, P
enecessarily, along with the rotating speed of gear type pump reduces, fluid flow reduces, P
palso reduce, therefore, the spool aperture of throttle compensating valve 4 reduces, and the flow flowing back to hydraulic reservoir through throttle compensating valve 4 and back oil road 7 reduces, thus ensure that the demand of the constant flow of door frame inclination and accessory function; When load is certain, P
enecessarily, along with the rotating speed of gear type pump is certain, fluid flow is determined, P
palso determine, the spool aperture of throttle compensating valve 4 is determined, the flow flowing back to hydraulic reservoir through throttle compensating valve 4 and back oil road 7 is determined, thus ensure that the demand of the constant flow of inclination and accessory function in front of the door, i.e. the constant airspeed of door frame inclination and accessory function.So ensure that fork truck has constant door frame and tilts and accessory responsiveness when zero load, thus make the speed of door frame inclination and accessory be unlikely to cause because of load too low speed too low, so that work efficiency is low; Meanwhile, ensure that fork truck be with carry time, is unlikely to make because of load variations door frame to tilt and the velocity variations of accessory, ensure that work efficiency, and the responsiveness avoiding door frame inclination and the accessory caused because load is excessive is too fast and there is fork truck potential safety hazard.
In other embodiments, described multiple directional control valve is not limited to 3 position-5 way valve, and described multiple directional control valve also can adopt the change-over valve of more than five-way.
Above-described embodiment is only used for further illustrating a kind of forklift hydraulic system with dynamic throttling speed control circuit of the present utility model; but the utility model is not limited to embodiment; every above embodiment is done according to technical spirit of the present utility model any simple modification, equivalent variations and modification, all fall in the protection domain of technical solutions of the utility model.
Claims (9)
1. be with a forklift hydraulic system for dynamic throttling speed control circuit, comprise multiple directional control valve, oil inlet P and oil return inlet T; It is characterized in that: also comprise throttle compensating valve, multiple directional control valve at least has oil inlet C, return opening D, oil outlet E, the first actuator port F and the second actuator port G, the oil inlet C of this multiple directional control valve is communicated with oil inlet P respectively with the oil inlet of throttle compensating valve, and the return opening D of multiple directional control valve is communicated with oil return inlet T respectively with the oil outlet of throttle compensating valve; When multiple directional control valve commutation is to the first working position, its first actuator port F is communicated with its oil inlet C and oil outlet E, and its second actuator port G is communicated with its return opening D; When multiple directional control valve commutation is to the second working position, its first actuator port F is communicated with its return opening D, and its second actuator port G is communicated with its oil inlet C and oil outlet E; The oil outlet E of multiple directional control valve is communicated with the control port at the place, one end with spring of throttle compensating valve, and the control port at one end place of throttle compensating valve not with spring is communicated with oil inlet P.
2. the forklift hydraulic system of the dynamic throttling speed control circuit of band according to claim 1, is characterized in that: also comprise by pass valve, and the oil inlet of this by pass valve is communicated with described oil inlet P with control port, and the oil outlet of this by pass valve is communicated with described oil return inlet T.
3. the forklift hydraulic system of the dynamic throttling speed control circuit of band according to claim 1, it is characterized in that: described multiple directional control valve, throttle compensating valve are integrated in a body, this body is provided with described oil inlet P, oil return inlet T, and the first pressure oil port A and the second pressure oil port B, first pressure oil port A is communicated with described first actuator port F, and the second pressure oil port B is communicated with described second actuator port G.
4. the forklift hydraulic system of the dynamic throttling speed control circuit of band according to claim 2, it is characterized in that: described multiple directional control valve, throttle compensating valve, by pass valve are integrated in a body, this body is provided with described oil inlet P, oil return inlet T, and the first pressure oil port A and the second pressure oil port B, first pressure oil port A is communicated with described first actuator port F, and the second pressure oil port B is communicated with described second actuator port G.
5. the forklift hydraulic system of the dynamic throttling speed control circuit of band according to claim 1, is characterized in that: the spring pre-tightening compressive force of described throttle compensating valve is adjustable.
6. the forklift hydraulic system of the dynamic throttling speed control circuit of band according to claim 1, is characterized in that: when described multiple directional control valve commutation is to the first working position, its first actuator port F adopts throttling passage to be communicated with oil inlet C; When described multiple directional control valve commutation is to the second working position, its second actuator port G adopts throttling passage to be communicated with oil inlet C.
7. the forklift hydraulic system of the dynamic throttling speed control circuit of band according to claim 1, is characterized in that: the first actuator port F of described multiple directional control valve is communicated with the rodless cavity hydraulic fluid port A of the operating cylinder of fork truck
t/c, the second actuator port G is communicated with the rod chamber hydraulic fluid port B of the operating cylinder of fork truck
t/c.
8. the forklift hydraulic system of the dynamic throttling speed control circuit of the band according to claim 3 or 4, is characterized in that: described first pressure oil port A is communicated with the rodless cavity hydraulic fluid port A of the operating cylinder of fork truck
t/c, the second pressure oil port B is communicated with the rod chamber hydraulic fluid port B of the operating cylinder of fork truck
t/c.
9. the forklift hydraulic system of the dynamic throttling speed control circuit of band according to claim 1, is characterized in that: described multiple directional control valve is 3 position-5 way valve.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520890382.XU CN205099287U (en) | 2015-11-10 | 2015-11-10 | Drive attitude throttle speed adjust loop's fork truck hydraulic system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201520890382.XU CN205099287U (en) | 2015-11-10 | 2015-11-10 | Drive attitude throttle speed adjust loop's fork truck hydraulic system |
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| Publication Number | Publication Date |
|---|---|
| CN205099287U true CN205099287U (en) | 2016-03-23 |
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ID=55515081
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105692509A (en) * | 2015-11-10 | 2016-06-22 | 林德（中国）叉车有限公司 | Forklift hydraulic system with dynamic throttling speed governing circuit |
-
2015
- 2015-11-10 CN CN201520890382.XU patent/CN205099287U/en active Active
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105692509A (en) * | 2015-11-10 | 2016-06-22 | 林德（中国）叉车有限公司 | Forklift hydraulic system with dynamic throttling speed governing circuit |
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