Disclosure of Invention
The present invention is directed to solving, at least to some extent, one of the technical problems in the related art.
Therefore, the invention aims to provide a control valve group for a hydraulic system of an electric forklift truck, which has a simple and energy-saving oil path.
Another object of the present invention is to provide an electric forklift hydraulic system having the above control valve set for an electric forklift hydraulic system.
According to the embodiment of the invention, the control valve group for the hydraulic system of the electric forklift comprises:
the overflow valve is provided with an overflow valve left connector and an overflow valve right connector;
the communicating control valve is provided with a communicating control valve lower interface, a communicating control valve upper interface, a communicating control valve left control cavity and a communicating control valve right control cavity, the communicating control valve lower interface and the communicating control valve left control cavity are both connected with the overflow valve left interface, and the communicating control valve upper interface is connected with the communicating control valve right control cavity;
the priority flow valve is provided with a lower priority flow valve interface, a first upper priority flow valve interface, a second upper priority flow valve interface, a left priority flow valve control cavity and a right priority flow valve control cavity, the lower priority flow valve interface is connected with the left overflow valve interface, the first upper priority flow valve interface is connected with the left priority flow valve control cavity, and the right priority flow valve control cavity is connected with the upper communication control valve interface;
the two-position two-way electromagnetic stop valve is provided with a lower interface of the two-position two-way electromagnetic stop valve and an upper interface of the two-position two-way electromagnetic stop valve, the lower interface of the two-position two-way electromagnetic stop valve is connected with the first upper interface of the priority flow valve, and the upper interface of the two-position two-way electromagnetic stop valve is connected with the upper interface of the communication control valve;
the proportional flow stop valve is provided with a lower interface of the proportional flow stop valve and an upper interface of the proportional flow stop valve, and the lower interface of the proportional flow stop valve is respectively connected with the upper interface of the two-position two-way electromagnetic stop valve and the upper interface of the communication control valve;
the overflow valve left interface forms a first interface of a control valve group for an electric forklift hydraulic system, the overflow valve right interface forms a second interface and a third interface of the control valve group for the electric forklift hydraulic system respectively, the priority flow valve second upper interface forms a fourth interface of the control valve group for the electric forklift hydraulic system, and the proportional flow stop valve upper interface forms a fifth interface of the control valve group for the electric forklift hydraulic system.
Advantageously, the left port of the overflow valve and the right port of the overflow valve are normally disconnected, the lower port of the communication control valve and the upper port of the communication control valve are normally disconnected, the lower port of the priority flow valve and the first upper port of the priority flow valve are normally connected, the lower port of the priority flow valve and the second upper port of the priority flow valve are normally disconnected, the lower port of the two-position two-way electromagnetic stop valve and the upper port of the two-position two-way electromagnetic stop valve are normally disconnected, and the lower port of the proportional flow stop valve and the upper port of the proportional flow stop valve are always in one-way connection from the lower port of the proportional flow stop valve to the upper port of the proportional.
Advantageously, the control valve group for the hydraulic system of the electric forklift further comprises a manual stop valve, wherein a first end of the manual stop valve is connected with the upper port of the proportional flow stop valve, and a second end of the manual stop valve is connected with the right port of the overflow valve.
According to the embodiment of the invention, the hydraulic system of the electric forklift comprises:
a control valve group for an electric fork-lift hydraulic system according to any one of the above;
a hydraulic pump-motor, an outlet of the hydraulic pump-motor being connected to the first interface;
a generator-motor connected to the hydraulic pump-motor;
the inlet of the hydraulic pump-motor and the second interface are connected with the oil tank;
the rodless cavity of the single-acting oil cylinder is connected with the fifth interface;
the fourth interface is suitable for assisting the utensil oil feed way with electric fork truck hydraulic pressure and links to each other, the third interface is suitable for assisting the oil return way of utensil with electric fork truck hydraulic pressure and links to each other.
Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
Detailed Description
Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.
A control valve block for an electric forklift hydraulic system according to an embodiment of the present invention will be described in detail below with reference to the accompanying drawings.
As shown in fig. 1 and 2, a control valve group 4 for a hydraulic system of an electric forklift according to an embodiment of the present invention includes: a relief valve 41, a communication control valve 42, a priority flow valve 43, a two-position two-way electromagnetic shutoff valve 44, and a proportional flow shutoff valve 45.
Specifically, the relief valve 41 has a relief valve left port a1 and a relief valve right port B1. The overflow valve left port A1 and the overflow valve right port B1 are disconnected.
The communication control valve 42 has a communication control valve lower port a2, a communication control valve upper port B2, a communication control valve left control chamber 42a, and a communication control valve right control chamber 42B. The lower communication control valve port A2 and the left communication control valve control cavity 42a are connected with the overflow valve port A1, and the upper communication control valve port B2 is connected with the right communication control valve control cavity 42B. The communication control valve lower port a2 is normally disconnected from the communication control valve upper port B2.
The priority flow valve 43 has a priority flow valve lower interface a3, a priority flow valve first upper interface B3, a priority flow valve second upper interface C3, a priority flow valve left control chamber 43a, and a priority flow valve right control chamber 43B. The lower interface A3 of the priority flow valve is connected with the left interface A1 of the overflow valve, the first upper interface B3 of the priority flow valve is connected with the left control cavity 43a of the priority flow valve, and the right control cavity 43B of the priority flow valve is connected with the upper interface B2 of the communication control valve. The priority flow valve lower interface A3 is normally open to the priority flow valve first upper interface B3 and the priority flow valve lower interface A3 is normally open to the priority flow valve second upper interface C3.
The two-position two-way electromagnetic cut-off valve 44 has a two-position two-way electromagnetic cut-off valve lower port A4 and a two-position two-way electromagnetic cut-off valve upper port B4. The lower connector A4 of the two-position two-way electromagnetic stop valve is connected with a first upper connector B3 of the priority flow valve, and the upper connector B4 of the two-position two-way electromagnetic stop valve is connected with an upper connector B2 of the communication control valve. The lower interface A4 of the two-position two-way electromagnetic stop valve is normally disconnected with the upper interface B4 of the two-position two-way electromagnetic stop valve.
The proportional flow cut-off valve 45 has a proportional flow cut-off valve lower port a5 and a proportional flow cut-off valve upper port B5. The lower port A5 of the proportional flow cut-off valve is respectively connected with the upper port B4 of the two-position two-way electromagnetic cut-off valve and the upper port B2 of the communication control valve. The lower port A5 of the proportional flow cut-off valve and the upper port B5 of the proportional flow cut-off valve are always in one-way communication from the lower port A5 of the proportional flow cut-off valve to the upper port B5 of the proportional flow cut-off valve.
The overflow valve left interface A1 forms a first interface P of a control valve group 4 for an electric forklift hydraulic system, the overflow valve right interface B1 forms a second interface T1 and a third interface T2 of the control valve group 4 for the electric forklift hydraulic system respectively, the priority flow valve second upper interface C3 forms a fourth interface B of the control valve group 4 for the electric forklift hydraulic system, and the proportional flow cut-off valve upper interface B5 forms a fifth interface A of the control valve group 4 for the electric forklift hydraulic system.
According to a specific example of the invention, the control valve group 4 for the hydraulic system of the electric forklift further comprises a manual cut-off valve 46, wherein a first end of the manual cut-off valve 46 is connected with the proportional flow cut-off valve upper connector B5, and a second end of the manual cut-off valve 46 is connected with the overflow valve right connector B1.
As shown in fig. 2, an electric forklift hydraulic system according to an embodiment of the present invention includes: the control valve group 4 for the hydraulic system of the electric forklift, the hydraulic pump-motor 1, the power generation-motor 2, the oil tank 3 and the single-acting oil cylinder 5 are arranged on the hydraulic system of the electric forklift.
Specifically, the outlet of the hydraulic pump-motor 1 is connected to the first port P.
The generator-motor 2 is connected to the hydraulic pump-motor 1, and the generator-motor 2 is used for driving the hydraulic pump-motor 1 to rotate forward or backward.
The inlet of the hydraulic pump-motor 1 and the second port T1 are connected to the oil tank 3.
The rodless cavity of the single-acting oil cylinder 5 is connected with the fifth interface A.
The fourth interface B is suitable for being connected with an oil supply way of the hydraulic auxiliary tool of the electric forklift, and the third interface T2 is suitable for being connected with an oil return way of the hydraulic auxiliary tool of the electric forklift.
In other words, the hydraulic system of the electric forklift according to the embodiment of the invention is composed of the generator-motor 2, the hydraulic pump-motor 1, the oil tank 3, the control valve group 4 for the hydraulic system of the electric forklift and the single-acting oil cylinder 5.
The control valve group 4 for the hydraulic system of the electric forklift is integrated with an overflow valve 41, a communication control valve 42, a priority flow valve 43, a two-position two-way electromagnetic stop valve 44, a proportional flow stop valve 45 and a manual stop valve 46.
A valve unit 4 for electric fork truck hydraulic system has first interface P, second interface T1, third interface T3, fourth interface B and fifth interface A, first interface P links to each other with hydraulic pump-motor 1's export, fourth interface B and electric fork truck hydraulic pressure assist the utensil oil supply way and link to each other, second interface T1 links to each other with oil tank 3, third interface T3 links to each other with the oil return way of electric fork truck hydraulic pressure assist the utensil, the no pole chamber of single-action hydro-cylinder 5 is connected to fifth interface A.
The working principle of the hydraulic system of the electric forklift according to the embodiment of the invention is as follows:
when the heavy object is controlled to ascend, the generator-motor 2 rotates forwards to enable the two-position two-way electromagnetic stop valve 44 to be in a conducting state in an electrified mode, the generator-motor 2 drives the hydraulic pump-motor 1 to be in a hydraulic pump working state, oil is sucked from the oil tank 3, then the oil enters a rodless cavity of the single-action oil cylinder 5 through the first interface P and the priority flow valve 43, then the oil enters the rodless cavity of the single-action oil cylinder 5 through the two-position two-way electromagnetic stop valve 44 and the proportional flow stop valve 45 to push the oil cylinder 5 to ascend, and the ascending speed can be controlled by. During the ascent, since the pressure of the communication control valve left control chamber 42a is greater than the pressure of the communication control valve right control chamber 42b, the communication control valve 42 is in the closed state. The priority flow valve 43 is preferentially supplied to the single-acting cylinder 5 according to the inlet flow, and the redundant flow is output to the fourth port B to supply the hydraulic auxiliary (i.e. if the inlet flow is larger, the lower port A3 of the priority flow valve is conducted with the first upper port B3 of the priority flow valve, and the lower port A3 of the priority flow valve is also conducted with the second upper port C3 of the priority flow valve).
When the heavy object stops, the two-position two-way electromagnetic stop valve 44 is powered off, the two-position two-way electromagnetic stop valve 44 is in a stop state, the single-acting oil cylinder 5 is locked, and if the generator-motor 2 rotates forwards at the moment, all the oil is output to the fourth interface B to be used by the hydraulic auxiliary tool.
When the heavy object is controlled to descend, a certain voltage signal of the proportional flow stop valve 45 is given to enable the heavy object to be in a reverse opening state, oil in a rodless cavity of the single-acting oil cylinder 5 acts on the right control cavity 42b of the communication control valve through the fifth interface A and the proportional flow stop valve 45, the communication control valve 42 is enabled to be switched to a communication state, the oil enters the hydraulic pump-motor 1 through the first interface P, the hydraulic pump-motor 1 is pushed to rotate to enable the hydraulic pump-motor to be in a hydraulic motor working state, the generator-motor 2 is further driven to rotate to generate electricity, and gravitational energy of the heavy object is converted into electric energy to be stored in. When the heavy object is controlled to descend, the descending speed can be controlled by controlling the voltage signal of the given proportional flow stop valve 4, and the descending speed is faster when the voltage signal is larger and the opening of the proportional flow stop valve 45 is larger. When the heavy object is controlled to descend, the pressure of the right control cavity 43B of the priority flow valve is larger than the pressure of the left control cavity 43a of the priority flow valve, the lower port A3 of the priority flow valve is communicated with the first upper port B3 of the priority flow valve, the lower port A3 of the priority flow valve is disconnected with the second upper port C3 of the priority flow valve, the fourth port B is not communicated with the first port P, and the descending of the heavy object cannot influence the hydraulic auxiliary tool.
When the electric forklift has circuit faults and cannot normally supply power, and heavy objects need to be placed, the opening degree of the manual stop valve 46 is adjusted, and the heavy objects are manually placed.
The invention has the beneficial effects that:
(1) the oil circuit is simple, and the hydrovalve that contains is small in quantity, and is with low costs to only 2 solenoid valves, compare in prior art, thereby the solenoid valve is small in quantity power consumptive little.
(2) The ascending speed and the descending speed can be controlled proportionally.
(3) When the device descends, energy can be recovered and saved.
In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the invention and to simplify the description, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and are therefore not to be considered limiting of the invention.
Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.
In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.
In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.
In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.
Although the embodiments of the present invention have been shown and described, it is understood that the embodiments are illustrative and not restrictive, and that those skilled in the art may make changes, modifications, substitutions and alterations to the embodiments without departing from the scope of the present invention.