Electric control brake valve group and tractor brake hydraulic system

Abstract

The utility model provides an electric control brake valve group and a tractor brake hydraulic system, the electric control brake valve group comprises a valve block, the valve block is provided with a pressure oil port, an oil return port, a left brake oil port and a right brake oil port, the valve block is internally provided with a front pressure reducing valve, a left electric proportional pressure reducing valve and a right electric proportional pressure reducing valve, an inlet end of the front pressure reducing valve is connected with a pressure oil port, oil return ends of the front pressure reducing valve, the left electric proportional pressure reducing valve and the right electric proportional pressure reducing valve are connected with an oil return port, and outlet end branches of the front pressure reducing valve are connected with inlet ends of the left electric proportional pressure reducing valve and the right electric proportional pressure reducing valve respectively. And the outlet ends of the left electric proportional pressure reducing valve and the right electric proportional pressure reducing valve are connected with left and right brake oil ports. By the adoption of the hydraulic system, oil pressure is limited within the allowable pressure limit value of the brake through the front pressure reducing valve, stepless change of the oil pressure is controlled through the electric proportional pressure reducing valve, and controllability of braking force is improved; and the risk of brake failure caused by frequent overpressure is avoided, and the riding comfort is good.

Description

Technical Field

[0001] The utility model relates to the technical field of tractor brake systems, in particular to an electrically controlled brake valve group and a tractor brake hydraulic system. Background Art

[0002] Currently, when a CVT tractor is unmanned, speed control relies on the hydraulic pump, travel motor, and high-pressure relief valve in the closed system. When the vehicle stops, the hydraulic pump stops working, and the travel motor rotates under its inertia. Some of the oil at its outlet flows back through the high-pressure relief valve to the inlet of the travel motor until the kinetic energy is exhausted and the travel motor stops. When the vehicle speed is high, the braking time is long and the braking process is uncontrollable, which is far from meeting the deceleration requirement of 2.5m / s. 2 braking requirements.

[0003] In terms of braking process reliability, there are no relevant mature technology application cases for domestic tractors. There are only technical solutions suitable for low-pressure braking systems: when controlling the speed, the low-pressure switching valve is frequently opened and closed to make the brake pressure oil change in a pulsed manner, achieving the effect of braking. There is no good and smooth braking force curve, the braking force is poorly controllable, there are safety hazards, and the riding comfort is affected. Utility Model Content

[0004] The technical problem to be solved by the utility model is: how to realize stepless change of braking force and improve the controllability of braking force.

[0005] The technical solution of the utility model to solve the above technical problems is as follows:

[0006] The utility model provides an electronically controlled brake valve group, comprising a valve block, wherein the valve block is provided with a pressure oil port, an oil return port, a left brake oil port and a right brake oil port; a pre-pressure reducing valve, a left electric proportional pressure reducing valve and a right electric proportional pressure reducing valve are provided in the valve block; the inlet end of the pre-pressure reducing valve is connected to the pressure oil port through an oil channel, the return oil end of the pre-pressure reducing valve, the return oil end of the left electric proportional pressure reducing valve and the return oil end of the right electric proportional pressure reducing valve are respectively connected to the return oil port through oil channels, the outlet end of the pre-pressure reducing valve is respectively connected to the inlet end of the left electric proportional pressure reducing valve and the inlet end of the right electric proportional pressure reducing valve through an oil channel branch, the outlet end of the left electric proportional pressure reducing valve is connected to the left brake oil port through an oil channel, and the outlet end of the right electric proportional pressure reducing valve is connected to the right brake oil port through an oil channel.

[0007] The beneficial effects of the utility model are:

[0008] By adopting the utility model, the oil pressure is limited to the allowable pressure limit of the brake through the front pressure reducing valve, the left electric proportional pressure reducing valve and the right electric proportional pressure reducing valve control the stepless change of the oil pressure, and the pressure oil is respectively supplied to the left and right brakes through the left brake oil port and the right brake oil port, thereby realizing stepless change of the braking force and improving the controllability of the braking force; avoiding the risk of brake failure due to frequent overpressure and improving the riding comfort.

[0009] On the basis of the above technical solution, the present invention can also be improved as follows.

[0010] Furthermore, the valve block is also provided with a left pressure measuring port and a right pressure measuring port, the left pressure measuring port connects the oil passage from the left electric proportional pressure reducing valve to the left brake oil port, and the right pressure measuring port connects the oil passage from the right electric proportional pressure reducing valve to the right brake oil port.

[0011] The left and right pressure measuring ports are connected to pressure monitoring instruments to facilitate monitoring of the brake oil pressure and improve the safety of the brake system.

[0012] Furthermore, the valve block is also provided with a left foot pump interface and a right foot pump interface;

[0013] A left shuttle valve is also provided on the oil passage from the left electric proportional pressure reducing valve to the left brake oil port, one end of the left shuttle valve is connected to the left interface of the foot pump through the oil passage, and the other end is connected to the outlet of the left electric proportional pressure reducing valve through the oil passage, and the middle outlet of the left shuttle valve is connected to the left brake oil port; a right shuttle valve is also provided on the oil passage from the right electric proportional pressure reducing valve to the right brake oil port, one end of the right shuttle valve is connected to the right interface of the foot pump through the oil passage, and the other end is connected to the outlet of the right electric proportional pressure reducing valve through the oil passage, and the middle outlet of the right shuttle valve is connected to the right brake oil port.

[0014] When unmanned driving and driver-operated active braking intervene at the same time, the oil pressure with higher braking pressure can be delivered to the left and right brakes through the left shuttle valve and the right shuttle valve, facilitating efficient deceleration or parking, and prioritizing braking safety.

[0015] Furthermore, the left pressure measuring port is connected to the oil passage from the left shuttle valve to the left brake oil port, and the right pressure measuring port is connected to the oil passage from the right shuttle valve to the right brake oil port.

[0016] It is convenient to accurately monitor the actual oil pressure obtained by the left and right brakes, thereby improving the accuracy of brake control.

[0017] Furthermore, a pressure oil pressure measuring port is provided on the valve block, and the pressure oil pressure measuring port is connected to the oil passage of the outlet of the pre-pressure reducing valve.

[0018] By connecting a pressure monitoring instrument through the pressure oil measuring port, it is convenient to monitor the oil pressure obtained by the electric proportional pressure reducing valve, which can determine the working status of the pre-pressure reducing valve and improve the safety of the braking system.

[0019] Furthermore, when the left electric proportional pressure reducing valve and the right electric proportional pressure reducing valve are in a power-off state, their own inlet ends are closed and their own outlet ends are connected to their own oil return ends.

[0020] In the power-off state, the output oil pressure of the left electric proportional pressure reducing valve and the right electric proportional pressure reducing valve is zero, avoiding the impact on manual driving.

[0021] Furthermore, the valve core of the left electric proportional pressure reducing valve and the valve core of the right electric proportional pressure reducing valve are both provided with a first working position and a second working position. When the first working position is working, the inlet end is closed and the outlet end is connected to its own oil return end; when the second working position is working, the oil return end is closed and the outlet end is connected to its own inlet end.

[0022] Simple structure and easy control.

[0023] Furthermore, the pre-pressure reducing valve is a mechanical pressure reducing valve.

[0024] The output pressure is stable, not affected by electrical signals, has a long service life, and improves the safety of the braking system.

[0025] Furthermore, a total oil return channel is provided in the valve block, and the oil return ends of the pre-pressure reducing valve, the left electric proportional pressure reducing valve and the right electric proportional pressure reducing valve are respectively connected to the total oil return channel, and the total oil return channel is connected to the oil return port.

[0026] The return oil is collected and discharged through the oil return port, which saves space and makes return oil processing convenient.

[0027] The utility model also provides a tractor brake hydraulic system, comprising a hydraulic pump, an oil tank, a left brake, a right brake and the above-mentioned electronically controlled brake valve group; the oil tank is respectively connected to the inlet of the hydraulic pump and the oil return port, the outlet of the hydraulic pump is connected to the pressure oil port, the pressure control oil port of the left brake is connected to the left brake oil port, and the pressure control oil port of the right brake is connected to the right brake oil port.

[0028] It realizes the infinite variation of braking force and improves the controllability of braking force; it avoids the risk of brake failure due to frequent overpressure and improves the riding comfort. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a structural diagram of the present utility model.

[0030] In the accompanying drawings, the technical features represented by the reference numerals are as follows:

[0031] 1-Pre-pressure reducing valve; 2-Left electric proportional pressure reducing valve; 3-Right electric proportional pressure reducing valve; 4-Left shuttle valve; 5-Right shuttle valve;

[0032] P-pressure oil port; T-return oil port; L-left brake oil port; L1-left foot pump interface; R-right brake oil port; R1-right foot pump interface; ML-left pressure measuring port; MR-right pressure measuring port; MP-pressure oil pressure measuring port. DETAILED DESCRIPTION

[0033] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0034] This utility model refers to Figure 1 .

[0035] The utility model provides an electronically controlled brake valve group, comprising a valve block, wherein the valve block is provided with a pressure oil port P, an oil return port T, a left brake oil port L and a right brake oil port R, and a pre-pressure reducing valve 1, a left electric proportional pressure reducing valve 2 and a right electric proportional pressure reducing valve 3 are provided in the valve block, the inlet end of the pre-pressure reducing valve 1 is connected to the pressure oil port P through an oil channel, the return oil end of the pre-pressure reducing valve 1, the return oil end of the left electric proportional pressure reducing valve 2 and the return oil end of the right electric proportional pressure reducing valve 3 are respectively connected to the return oil port T through oil channels, the outlet end of the pre-pressure reducing valve 1 is respectively connected to the inlet end of the left electric proportional pressure reducing valve 2 and the inlet end of the right electric proportional pressure reducing valve 3 through an oil channel branch, the outlet end of the left electric proportional pressure reducing valve 2 is connected to the left brake oil port L through an oil channel, and the outlet end of the right electric proportional pressure reducing valve 3 is connected to the right brake oil port R through an oil channel.

[0036] principle:

[0037] During installation, connect pressure port P to a pressure oil source such as an oil pump, return port T to the oil tank, left brake port L to the left brake's pressure control port, and right brake port R to the right brake's pressure control port. During operation, pre-pressure reducing valve 1 limits the oil pressure to the brake's allowable pressure limit, with excess oil pressure overflowing to return port T. This prevents excessive inlet pressure from the electric proportional pressure reducing valve directly limiting the high pressure, leading to malfunction and brake overload. This also reduces the risk of brake failure due to frequent overpressure. The left and right electric proportional pressure reducing valves 2 and 3 control the valve core's movement using their own input current. The valve opening is infinitely adjustable, allowing for stepless control of the oil pressure output to the brakes, ensuring smooth variations in braking force.

[0038] With the present utility model, the oil pressure is limited to the allowable pressure limit of the brake through the front pressure reducing valve 1, the left electric proportional pressure reducing valve 2 and the right electric proportional pressure reducing valve 3 control the stepless change of the oil pressure, and provide pressurized oil to the left and right brakes through the left brake oil port L and the right brake oil port R respectively, thereby realizing stepless change of braking force and improving the controllability of braking force; avoiding the risk of brake failure caused by frequent overpressure and improving riding comfort.

[0039] Furthermore, the valve block is also provided with a left pressure measuring port ML and a right pressure measuring port MR. The left pressure measuring port ML connects the oil passage from the left electric proportional pressure reducing valve 2 to the left brake oil port L, and the right pressure measuring port MR connects the oil passage from the right electric proportional pressure reducing valve 3 to the right brake oil port R.

[0040] The pressure monitoring instrument is connected through the left pressure measuring port ML and the right pressure measuring port MR to facilitate monitoring of the brake oil pressure and improve the safety of the brake system.

[0041] Furthermore, the valve block is also provided with a foot pump left interface L1 and a foot pump right interface R1;

[0042] A left shuttle valve 4 is further provided on the oil passage from the left electric proportional pressure reducing valve 2 to the left brake oil port L. One end of the left shuttle valve 4 is connected to the left interface L1 of the foot pump through the oil passage, and the other end is connected to the outlet of the left electric proportional pressure reducing valve 2 through the oil passage. The middle outlet of the left shuttle valve 4 is connected to the left brake oil port L.

[0043] A right shuttle valve 5 is also provided on the oil passage from the right electric proportional pressure reducing valve 3 to the right brake oil port R. One end of the right shuttle valve 5 is connected to the right interface R1 of the foot pump through the oil passage, and the other end is connected to the outlet of the right electric proportional pressure reducing valve 3 through the oil passage. The middle outlet of the right shuttle valve 5 is connected to the right brake oil port R.

[0044] Note: The foot pump is an existing technology of the tractor brake system. When the brake pedal is pressed, the foot pump works to provide brake pressure oil, and the brake pressure oil is input to the left port L1 and the right port R1 of the foot pump.

[0045] When unmanned driving and driver-initiated braking are simultaneously involved, the oil pressure with higher braking pressure can be delivered to the left and right brakes through the left shuttle valve 4 and the right shuttle valve 5, facilitating efficient deceleration or parking, giving priority to ensuring braking safety.

[0046] Furthermore, the left pressure measuring port ML is connected to the oil passage from the left shuttle valve 4 to the left brake oil port L, and the right pressure measuring port MR is connected to the oil passage from the right shuttle valve 5 to the right brake oil port R.

[0047] It is convenient to accurately monitor the actual oil pressure obtained by the left and right brakes, thereby improving the accuracy of brake control.

[0048] Furthermore, a pressure oil pressure measuring port MP is provided on the valve block, and the pressure oil pressure measuring port MP is connected to the oil passage at the outlet of the pre-pressure reducing valve 1 .

[0049] The pressure monitoring instrument is connected through the pressure oil measuring port MP to monitor the oil pressure obtained by the electric proportional pressure reducing valve, thereby judging the working status of the pre-pressure reducing valve 1 and improving the safety of the brake system.

[0050] Furthermore, when the left electric proportional pressure reducing valve 2 and the right electric proportional pressure reducing valve 3 are in a power-off state, their own inlet ends are closed and their own outlet ends are connected to their own oil return ends.

[0051] In the power-off state, the output oil pressure of the left electric proportional pressure reducing valve 2 and the right electric proportional pressure reducing valve 3 is zero, thus avoiding the influence on manual driving.

[0052] Furthermore, the valve core of the left electric proportional pressure reducing valve 2 and the valve core of the right electric proportional pressure reducing valve 3 are both provided with a first working position and a second working position. When the first working position is working, the inlet end is closed and the outlet end is connected to its own oil return end; when the second working position is working, the oil return end is closed and the outlet end is connected to its own inlet end.

[0053] Note: The proportional pressure reducing valve controls the valve core's movement through its own input current. It operates when either the first or second position moves to the inlet end of the electric proportional pressure reducing valve. The valve core is provided with a valve channel that connects or closes the different ports.

[0054] Simple structure and easy control.

[0055] Furthermore, the pre-pressure reducing valve 1 is a mechanical pressure reducing valve.

[0056] The output pressure is stable, not affected by electrical signals, has a long service life, and improves the safety of the braking system.

[0057] Furthermore, a total oil return channel is provided in the valve block, and the oil return ends of the pre-pressure reducing valve 1, the left electric proportional pressure reducing valve 2 and the right electric proportional pressure reducing valve 3 are respectively connected to the total oil return channel, and the total oil return channel is connected to the oil return port T.

[0058] The return oil is collected and discharged through the oil return port T, which saves space and facilitates the return oil treatment.

[0059] The utility model also provides a tractor brake hydraulic system, comprising a hydraulic pump, an oil tank, a left brake, a right brake and the above-mentioned electronically controlled brake valve group; the oil tank is respectively connected to the inlet of the hydraulic pump and the oil return port T, the outlet of the hydraulic pump is connected to the pressure oil port P, the pressure control oil port of the left brake is connected to the left brake oil port L, and the pressure control oil port of the right brake is connected to the right brake oil port R.

[0060] It realizes the infinite variation of braking force and improves the controllability of braking force; it avoids the risk of brake failure due to frequent overpressure and improves the riding comfort.

[0061] In the description of the present invention, it should be understood that if there are descriptive terms indicating orientation, direction or positional relationship, such as: "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., the orientation or positional relationship indicated in this specification is based on the orientation or positional relationship shown in the accompanying drawings, which is only for the convenience of understanding the present invention and simplifying the description, and does not indicate or imply that the referred part, element or whole must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0062] In addition, if there are order description terms, such as "first", "second", etc., their use in this specification is to facilitate understanding or simplify the description. For example, in order to distinguish multiple technical features with the same type or function, but they have to be mentioned separately, this specification may use prefix or suffix order description terms to distinguish them. Therefore, it cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" can explicitly or implicitly include at least one of such features. In the description of this utility model, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0063] In the present invention, if terms describing the relative functional relationship of structures are used, such as "install", "connect", "connect", "fix", etc., they should be understood in a broad sense unless otherwise clearly specified and limited. For example, "install", "connect", "connect", etc. can be fixed connections, detachable connections, or integrated; can be mechanical connections or electrical connections; can be direct connections or indirect connections through an intermediate medium, can be internal connections between two elements or interactive relationships between two elements; "fix" can be fixed to form an integral body, or can be detachably fixed through fasteners; can be directly fixed or fixed through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above-mentioned descriptive terms in the present invention can be understood according to the specific circumstances, the context, the coherence of the preceding and following texts, etc.

[0064] In this utility model, if descriptive terms with ancillary or connecting meaning appear, for example, a first feature being "on" or "below" a second feature, these should not be interpreted as limiting unless otherwise expressly specified or limited. For example, "on" or "below" may refer to direct contact between the first and second features, or indirect contact between the first and second features through an intermediary. Those skilled in the art will understand the specific meanings of these descriptive terms in this utility model based on the specific circumstances, context, and coherence of the preceding and following texts.

[0065] Furthermore, when a first feature is “above,” “above,” or “above” a second feature, it may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. When a first feature is “below,” “below,” or “below” a second feature, it may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0066] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. In addition, those skilled in the art may combine and combine the different embodiments, examples and features of different embodiments and examples described in this specification, unless there is any contradiction, and these combinations or combinations should all fall within the scope summarized by the present invention.

[0067] Although the embodiments of the present invention have been shown and described above, it is understood that the above embodiments are illustrative and cannot be understood as limiting the present invention. Changes, modifications, substitutions and variations of the above embodiments made by ordinary technicians in the field within the scope of information available from public channels and in combination with the technical inspiration given by the application documents are still within the scope of protection of the present application.

Claims

1. An electronically controlled brake valve group, characterized in that: The invention comprises a valve block, wherein the valve block is provided with a pressure oil port (P), an oil return port (T), a left brake oil port (L) and a right brake oil port (R); a pre-pressure reducing valve (1), a left electric proportional pressure reducing valve (2) and a right electric proportional pressure reducing valve (3) are provided in the valve block; the inlet end of the pre-pressure reducing valve (1) is connected to the pressure oil port (P) through an oil passage; the oil return end of the pre-pressure reducing valve (1), the oil return end of the left electric proportional pressure reducing valve (2) and the oil return end of the right electric proportional pressure reducing valve (3) are respectively connected to the oil return port (T) through oil passages; the outlet end of the pre-pressure reducing valve (1) is respectively connected to the inlet end of the left electric proportional pressure reducing valve (2) and the inlet end of the right electric proportional pressure reducing valve (3) through an oil passage branch; the outlet end of the left electric proportional pressure reducing valve (2) is connected to the left brake oil port (L) through an oil passage; and the outlet end of the right electric proportional pressure reducing valve (3) is connected to the right brake oil port (R) through an oil passage.

2. The electrically controlled brake valve assembly according to claim 1, characterized in that: The valve block is also provided with a left pressure measuring port (ML) and a right pressure measuring port (MR). The left pressure measuring port (ML) is connected to the oil passage from the left electric proportional pressure reducing valve (2) to the left brake oil port (L), and the right pressure measuring port (MR) is connected to the oil passage from the right electric proportional pressure reducing valve (3) to the right brake oil port (R).

3. The electrically controlled brake valve assembly according to claim 2, characterized in that: The valve block is also provided with a left foot pump interface (L1) and a right foot pump interface (R1); A left shuttle valve (4) is further provided on the oil passage from the left electric proportional pressure reducing valve (2) to the left brake oil port (L); one end of the left shuttle valve (4) is connected to the left interface (L1) of the foot pump via the oil passage, and the other end is connected to the outlet of the left electric proportional pressure reducing valve (2) via the oil passage; the middle outlet of the left shuttle valve (4) is connected to the left brake oil port (L); A right shuttle valve (5) is also provided on the oil passage from the right electric proportional pressure reducing valve (3) to the right brake oil port (R). One end of the right shuttle valve (5) is connected to the right interface (R1) of the foot pump through the oil passage, and the other end is connected to the outlet of the right electric proportional pressure reducing valve (3) through the oil passage. The middle outlet of the right shuttle valve (5) is connected to the right brake oil port (R).

4. The electrically controlled brake valve assembly according to claim 3, characterized in that: The left pressure measuring port (ML) is connected to the oil passage from the left shuttle valve (4) to the left brake oil port (L), and the right pressure measuring port (MR) is connected to the oil passage from the right shuttle valve (5) to the right brake oil port (R).

5. The electrically controlled brake valve assembly according to claim 1, characterized in that: The valve block is also provided with a pressure oil measuring port (MP), which is connected to the oil passage at the outlet of the pre-pressure reducing valve (1).

6. The electrically controlled brake valve assembly according to claim 1, characterized in that: When the power is off, the left electric proportional pressure reducing valve (2) and the right electric proportional pressure reducing valve (3) have their own inlet ends closed and their own outlet ends connected to their own oil return ends.

7. The electrically controlled brake valve assembly according to claim 6, characterized in that: The valve core of the left electric proportional pressure reducing valve (2) and the valve core of the right electric proportional pressure reducing valve (3) are both provided with a first working position and a second working position. When the first working position is in operation, the inlet end is closed and the outlet end is connected to its own oil return end; when the second working position is in operation, the oil return end is closed and the outlet end is connected to its own inlet end.

8. The electrically controlled brake valve assembly according to claim 1, characterized in that: The pre-pressure reducing valve (1) is a mechanical pressure reducing valve.

9. The electrically controlled brake valve assembly according to claim 1, characterized in that: A total oil return channel is provided in the valve block, and the oil return end of the pre-pressure reducing valve (1), the oil return end of the left electric proportional pressure reducing valve (2), and the oil return end of the right electric proportional pressure reducing valve (3) are respectively connected to the total oil return channel, and the total oil return channel is connected to the oil return port (T).

10. A tractor brake hydraulic system, characterized in that: It includes a hydraulic pump, an oil tank, a left brake, a right brake and the electronically controlled brake valve group according to any one of claims 1 to 9; the oil tank is respectively connected to the inlet of the hydraulic pump and the return oil port (T), the outlet of the hydraulic pump is connected to the pressure oil port (P), the pressure control oil port of the left brake is connected to the left brake oil port (L), and the pressure control oil port of the right brake is connected to the right brake oil port (R).

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