An anti-flameout device

Abstract

The present application relates to a kind of anti-flameout device, belong to engineering machinery equipment technical field.The anti-flameout device is located between gear pump and plunger pump control variable mechanism;Anti-flameout device includes a valve body, the passage of hydraulic oil import and export is equipped in valve body, hydraulic oil enters end and gear pump connection, and hydraulic oil flows out end and plunger pump control variable mechanism connection;The opening of hydraulic oil flow end is the structure of automatic variable diameter.By the present application, the pilot control oil pressure provided by gear pump is first introduced into anti-flameout device, and anti-flameout device automatically adjusts output control oil pressure according to the height of engine speed, and control oil pressure is provided to control handle again.In the high load operating condition, the output flow of plunger pump is automatically reduced, and the automatic matching of plunger pump input power and engine output power is realized, the operation labor intensity is reduced, the operation skill requirement is reduced, and the operation efficiency is improved.

Description

Technical Field

[0001] This invention relates to an anti-flameout device, belonging to the technical field of engineering machinery equipment. Background Technology

[0002] In a hydraulically controlled variable displacement piston pump, the pump's variable displacement is achieved through hydraulic control. The pump's output flow rate is directly proportional to the control fluid pressure output after the pilot handle depressurizes; the higher the control fluid pressure, the greater the output flow rate, and vice versa. The hydraulic pressure controlling the pump's variable displacement is determined by the opening degree of the pilot control handle, as shown in the attached diagram. Figure 1 The figure shows the control curve characteristics of a certain pilot handle. The horizontal axis represents the control angle of the handle, and the vertical axis represents the output hydraulic pressure of the pilot handle. It can be seen that the output control hydraulic pressure is determined by the working angle of the working handle. The characteristic curve of the control handle that has been installed cannot be changed.

[0003] As attached Figure 2 As shown, the control fluid pressure output by the control handle is connected to the receiving signal ports X1 and X2 of the control variable mechanism of the plunger pump. When port X1 receives a control signal, the plunger pump outputs flow rate, the magnitude of which changes with the output signal of the control fluid pressure. Port X2 is mainly used for oil venting to ensure that the control variable system is not trapped. When port X2 receives a signal, the output flow direction of the plunger pump changes, and port X1 is mainly used for oil venting. The control signals of X1 and X2 are determined by the direction controlled by the pilot control handle. Pushing the pilot handle forward can be defined as X1 control port, and X2 port is used for pressure venting; pulling the pilot handle backward can be defined as X2 control port, and X1 port is used for pressure venting. The schematic diagram of the control variable mechanism is shown below. Figure 2 As shown.

[0004] The closed-type plunger pump involved in this invention is mainly used to drive the skid steer loader to move. When the skid steer loader is shoveling forward, the high load P it receives is transmitted to the plunger pump. Assuming the output flow rate of the plunger pump is Q, then the input power of the plunger pump at this time is p = P * Q / 600. To ensure that the skid steer loader can operate normally at this time, the output power p1 of the engine needs to be greater than the input power p of the plunger to ensure that the skid steer loader does not stall. The maximum output power of a skid steer loader is set at the factory. The load P in the plunger pump input power p = P*Q / 600 is determined by the resistance during the skid steer's forward movement and loading, which cannot be directly controlled by a human. To ensure that the plunger pump's input power does not exceed the engine's output power, the plunger pump's output flow rate needs to be manually controlled during operation. The plunger pump's output flow rate is determined by the control hydraulic pressure, which is determined by the angle (opening) of the control handle. Therefore, this control mode places stringent demands on the operator: during loading, the operator must constantly sense changes in load and adjust the plunger pump's output flow rate by adjusting the angle of the control handle to change the control hydraulic pressure output, thus matching the engine's output power. The consequences are: 1. Poor driving experience and high workload, requiring intense concentration to complete the work; 2. Requires operators to possess certain driving skills, otherwise, the work cannot be completed; 3. Low efficiency, as prolonged work makes perfect power matching impossible, leading to engine stalling and repeated restarts, which further reduces work efficiency. Therefore, there is an urgent need in this technical field for a control device that can sense external high load signals, automatically reduce the output flow of the plunger pump, and achieve automatic matching between the input power of the plunger pump and the output power of the engine, so as to solve the problems faced in the prior art. Summary of the Invention

[0005] The purpose of this invention is to solve the technical problem of how to obtain a control device capable of sensing external high load signals, automatically reducing the output flow of the plunger pump, and achieving automatic matching between the input power of the plunger pump and the output power of the engine. This control device can receive high load signals during skid loading, automatically reduce the control hydraulic pressure that controls the output flow of the plunger pump, and automatically achieve matching between the plunger pump and engine power.

[0006] To achieve the goal of solving the above problems, the technical solution adopted by the present invention is to provide an anti-flameout device, which is located between the gear pump and the plunger pump control variable mechanism; the anti-flameout device includes a valve body, in which a hydraulic oil inlet and outlet channel is provided, the hydraulic oil inlet end is connected to the gear pump, and the hydraulic oil outlet end is connected to the plunger pump control variable mechanism; the opening of the hydraulic oil outlet end has an automatically variable diameter structure.

[0007] Preferably, the hydraulic oil outlet includes a fixed opening one on the valve body and a movable opening two inside the valve body; the opening one and the opening two are connected to form the hydraulic oil outlet, which has an automatically variable diameter structure.

[0008] Preferably, a fixed cylindrical large valve sleeve is provided in the valve body; a through hole one for hydraulic oil to flow out is provided on the side wall of the large valve sleeve; a movable cylindrical small valve sleeve is provided in the large valve sleeve; a through hole two communicating with the through hole one is provided on the side wall of the small valve sleeve; the through hole one and the through hole two form a hydraulic oil outflow opening with variable diameter.

[0009] Preferably, the anti-flameout device includes a valve seat connected to the valve body; an adjustment mechanism for adjusting the size of the hydraulic oil outflow opening is provided in the valve seat.

[0010] Preferably, the adjusting mechanism includes an adjusting screw passing through the end of the small valve sleeve away from the hydraulic oil inlet of the valve body; and an annular throttling gasket is provided at the end of the small valve sleeve near the hydraulic oil inlet of the valve body.

[0011] Preferably, the adjusting screw is fitted with a spring and spring seats at both ends of the spring; the spring abuts against the small valve sleeve through the spring seat at one end.

[0012] Preferably, the valve body has a valve seat at the end away from the hydraulic oil inlet, and the adjusting screw passes through the valve seat; a fixing nut and a nut are sequentially provided at the end of the adjusting screw away from the small valve sleeve; a locking nut is provided at the end of the adjusting screw close to the small valve sleeve, and a pad is provided between the locking nut and the spring seat.

[0013] Preferably, the adjusting screw is connected to the valve seat via a thread; the valve seat is fixedly connected to the valve body.

[0014] Preferably, a copper sleeve is provided between the large valve sleeve and the small valve sleeve.

[0015] Preferably, the end of the small valve sleeve away from the hydraulic oil inlet of the valve body is provided with a retaining ring that abuts against the spring seat.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] Existing skid steer loader control systems supply pilot oil to the control handle via a gear pump. The gear pump's built-in relief valve ensures a constant pilot pressure, and the piston pump's output flow rate is determined by the control handle's opening. Compared to existing skid steer loader control systems, this invention provides an anti-stalling device. The pilot oil supplied to the control handle by the gear pump is first introduced into this device. The anti-stalling device automatically adjusts the control oil pressure based on the engine speed, achieving a first-stage pressure reduction. This reduced control oil pressure is then supplied to the control handle. The piston pump's output flow rate is adjusted according to the handle's opening, automatically matching the piston pump's input power with the engine's output power. This reduces operator workload, lowers skill requirements, and improves operational efficiency. Attached Figure Description

[0018] Figure 1 The control characteristic curve of a certain pilot handle;

[0019] Figure 2 This is a schematic diagram of the control variable structure of a plunger pump;

[0020] Figure 3 A schematic diagram of an anti-flameout device provided by the present invention;

[0021] Figure 4 This is a schematic diagram of the external shape of an anti-flameout device provided by the present invention;

[0022] Figure 5 The diagram illustrates the relationship between traditional control logic and the logic of this invention.

[0023] Figure 6 This is a schematic diagram of a partial component of an anti-flameout device provided by the present invention;

[0024] Figure 7 A schematic diagram of the installation position of the anti-flameout device on a plunger pump provided by the present invention;

[0025] Reference numerals in the attached diagram: 1. Large valve sleeve; 2. Retaining ring one; 3. Throttling gasket; 4. Small valve sleeve; 5. Copper sleeve; 6. Retaining ring two; 7. O-ring one; 8. Locking nut; 9. Spacer; 10. Spring seat; 11. Spring; 12. Retaining ring three; 13. Adjusting screw; 14. Valve body; 15. Valve seat; 16. O-ring two; 17. Nut; 18. Nut. Detailed Implementation

[0026] To make the present invention more apparent and understandable, preferred embodiments are described in detail below with reference to the accompanying drawings:

[0027] like Figure 1-7As shown, this invention provides an anti-flameout device, which is disposed between a gear pump and a plunger pump control variable mechanism. The anti-flameout device includes a valve body 14, which has a hydraulic oil inlet and outlet channel. The hydraulic oil inlet end G is connected to the gear pump, and the hydraulic oil outlet end G1 is connected to the plunger pump control variable mechanism. The opening of the hydraulic oil outlet end has an automatically variable diameter structure. The hydraulic oil outlet end includes a fixed opening one on the valve body and a movable opening two inside the valve body; the opening one and opening two are connected to form an automatically variable diameter opening of the hydraulic oil outlet end. A fixed cylindrical large valve sleeve 1 is inserted through the valve body 14; the side wall of the large valve sleeve 1 has a through hole one for hydraulic oil outflow; a movable cylindrical small valve sleeve 4 is inserted through the large valve sleeve 1; the side wall of the small valve sleeve 4 has a through hole two communicating with the through hole one; the through hole one and through hole two form a variable diameter hydraulic oil outflow opening. The anti-flameout device includes a valve seat 15, which is connected to the valve body 14. An adjusting mechanism for regulating the size of the hydraulic oil outlet opening is installed in the valve seat 15. The adjusting mechanism includes an adjusting screw 13 inserted at the end of a small valve sleeve 4 away from the hydraulic oil inlet of the valve body; an annular throttling washer 3 is provided at the end of the small valve sleeve 4 near the hydraulic oil inlet of the valve body. A spring 11 and spring seats 10 at both ends of the spring 11 are fitted around the outer periphery of the adjusting screw 13; the spring 11 abuts against the small valve sleeve 4 through the spring seat 10 at one end. The valve body 14 has a valve seat 15 at the end away from the hydraulic oil inlet of the valve body, and the adjusting screw 13 passes through the valve seat 15. A fixing nut 17 and a nut 18 are sequentially provided at the end of the adjusting screw 13 away from the small valve sleeve 4; a locking nut 8 is provided at the end of the adjusting screw 13 near the small valve sleeve 4, and a pad 9 is provided between the locking nut 8 and the spring seat 10. The adjusting screw 13 is connected to the valve seat 15 via a thread; the valve seat 15 is fixedly connected to the valve body 14. A copper sleeve 5 is provided between the large valve sleeve 1 and the small valve sleeve 4. The end of the small valve sleeve 4 away from the hydraulic oil inlet of the valve body is provided with a retaining ring 3 12 that abuts against the spring seat 10.

[0028] Example

[0029] This embodiment discloses an anti-flameout device, including a large valve sleeve 1, a first retaining ring 2, a throttling gasket 3, a small valve sleeve 4, a copper sleeve 5, a second retaining ring 6, an first O-ring 7, a locking nut 8, a pad 9, a spring seat 10, a spring 11, a third retaining ring 12, an adjusting screw 13, a valve body 14, a valve seat 15, a second O-ring 16, a nut 17, and a screw cap 18.

[0030] The spring seat 10 is assembled to the outer periphery of the adjusting screw 13, with the right side limited by the end face. The right side of the adjusting screw 13 has an external hexagonal structure for easy adjustment. The spring 11 is assembled into the spring seat 10, with the spring seat 10 assembled on the left side, supported by the pad 9, and then locked by the lock nut 8 to form a small assembly.

[0031] Throttling gasket 3 is placed at one end of small valve sleeve 4, and retaining ring 2 fixes throttling gasket 3 through snap ring groove on small valve sleeve 4.

[0032] The inner hole of the copper sleeve 5 is fitted with the outer circle of the small valve sleeve 4 with a small clearance, and the retaining ring 6 fixes the copper sleeve 5 through the retaining ring groove on the small valve sleeve 4.

[0033] Assemble the locking nut 8, pad 9, spring seat 10, spring 11, and adjusting screw 13 to form a small component. Insert the small component into the small valve sleeve 4 from the left side. The retaining ring 3 12 fixes the spring seat 10 through the snap ring groove in the small valve sleeve 4.

[0034] The small assembly consisting of retaining ring 12, throttling gasket 3, copper sleeve 5, retaining ring 6, and adjusting screw 13 is installed into the small valve sleeve 4. The adjusting screw 13 is connected to the valve seat 15 by threads.

[0035] O-ring 16, nut 17, and screw 18 seal the adjustment position.

[0036] The valve seat 15 is threaded onto the valve body 14 and the hydraulic oil is sealed by an O-ring and a 7-corner seal.

[0037] The valve body 14 is secured to the plunger pump by three screws.

[0038] The pilot oil supplied by the gear pump to the pilot handle enters the anti-flameout device through port G. At this time, the oil pressure is P1, which is determined by the gear pump overflow valve. The inner area of ​​the large valve sleeve 1 is A1. Taking the small valve sleeve 4 as the equilibrium object, the equilibrium equation is P1×A1=P2×A1+P3×A2+F. The left side of the equation represents the rightward force exerted by the P1 pressure on the small valve sleeve 4. After the throttling effect of the throttling gasket 3, the oil pressure of P1 drops to P2 and enters the oil chamber T. The P2 pressure oil exerts a leftward hydraulic pressure on the small valve sleeve 4, with an area of ​​A1 and a pressure magnitude of P2×A1. The P3 pressure is the pressure flowing out from port H, from port G1 of the anti-flameout device to the control handle. Its magnitude is positively correlated with the opening X formed by the large valve sleeve 1 and the small valve sleeve 4, which is also an important position for the realization of the anti-flameout device function provided by this invention. P3 exerts a leftward hydraulic pressure on the small valve sleeve 4, with an area of ​​A2 and a magnitude of P3×A2. F 弹簧 The force is the leftward compressive force generated by the adjusting screw 13 compressing the spring 11 on the small valve sleeve 4. Converting the balance method, we get P3 = [(P1-P2)*A1-F]. 弹簧 The pressure difference ΔP = P1 - P2 formed by the thin-walled orifice of the throttling gasket 3 through P1 is determined by the throttling formula of the thin-walled orifice. achievable In Equation 1, P3 is the pilot pressure output by the gear pump after passing through the anti-flameout device. Its magnitude is determined by the size of the X opening. Based on the above theoretical analysis, the present invention will be described in detail.

[0039] In traditional skid steer control systems, the pilot oil for the control handle is supplied by a gear pump, and the output pressure is fixed by a built-in relief valve in the gear pump. The pilot control pressure output by the gear pump flows through the control handle. The larger the opening of the control handle, the smaller the pressure reduction effect, and the higher the control oil pressure flowing into the piston pump's control variable signal ports X1 or X2. This results in a larger output flow rate from the piston pump; here, the pilot handle acts as a pressure reducing valve. In this control method, the pilot control oil pressure input to the control handle remains constant. When the skid steer loader encounters a high load, reducing the control opening of the pilot handle only enhances the pressure reduction effect, decreasing the pressure flowing into the piston pump's control variable signal ports X1 and X2, thus reducing the piston pump's output flow rate and achieving a match between the piston pump's input power and the engine's output power.

[0040] Based on the principle of engine stalling: the direct cause of stalling is that the torque output by the engine output shaft is less than the resistance torque of the load, causing the engine to stop turning, first the speed decreases, and finally there is no speed, and the engine stalls. The anti-stalling device provided by this invention utilizes the relationship between engine speed and load, converting the speed change signal into a P3 pressure value signal, and then into a pilot oil pressure signal input to the control handle. Specifically, the fixed pilot oil pressure provided by the gear pump to the control handle is first introduced into the anti-stalling device. The anti-stalling device automatically adjusts the output pressure P3 according to the engine speed. The P3 pressure oil is connected from port H through port G1 of the anti-stalling device to the control handle, and then transmitted to the plunger pump control variable signal receiving ports X1 and X2 according to the handle's opening.

[0041] The control logic is as follows: When the skid steer loader is performing a loading operation, the travel device encounters a high load, which is transmitted to the piston pump. If the control handle opening remains unchanged, the piston pump displacement V is fixed, meaning the output flow rate is constant, and the output flow rate Q = n (speed) × V (displacement). At this time, the input power of the piston pump may exceed the engine output power. The engine experiences a large external load resistance torque, and the output shaft begins to decelerate. It can be seen that, given a constant opening area AO of the throttling gasket 3, oil density ρ, and spring force, the oil pressure at port P3 is related to Q. 2 Since Q is directly proportional to the engine speed n, P3 is naturally directly proportional to the engine speed n. When the engine speed n decreases, the piston pump output Q decreases, and the oil pressure of P3 decreases. Therefore, even if the opening of the control handle does not change, because the pilot oil pressure input to the control handle is reduced, the control oil pressure input to the piston pump control variable mechanism X1 and X2 signal ports also decreases accordingly. This reduces the piston pump displacement and the input power until it automatically matches the engine output power.

[0042] From Equation 1 above, it can be seen that the opening area AO of P3 and the throttling gasket 3 is... 2Inversely proportional, by changing the opening area A0, the slope of the equation relating pressure P3 and rotational speed can be changed; the larger the opening area, the smaller the slope. Adjusting spring F 弹簧 The initial pre-compression can change the starting point of the F3 pressure change; the greater the spring pre-compression, the lower the starting point. Therefore, it can be seen that the anti-flameout structure provided by this invention, through reasonable design of the opening area of ​​the throttling shim 3 and adjustment of the spring pre-compression, can change the characteristic curve of the output pressure P3 versus the rotational speed n, suitable for various control characteristic requirements.

[0043] Based on the principles of the innovative design of this invention and the structure of the anti-flameout device provided by this invention, the working process of the anti-flameout device provided by this invention will be described as follows:

[0044] The present invention provides an anti-flameout device secured to a plunger pump by three screws. Pilot control hydraulic oil P1 from the gear pump enters the anti-flameout device through the pipe joint at port G, acting on the left side of the small valve sleeve 4, generating a rightward pressure on the small valve sleeve 4. Simultaneously, the pressure oil passes through the throttling gasket 3, reducing the pressure loss to P2, generating a leftward hydraulic pressure on the small valve sleeve 4. The hydraulic oil passes through opening X, forming an oil pressure P3, which generates a leftward hydraulic pressure on the small valve sleeve 4. Spring 11 generates a leftward pre-compression force on the small valve sleeve 4, yielding the equilibrium equation P1×A1=P2×A1+P3×A2+F. 弹簧 The equation is transformed into It can be seen that the small valve sleeve 4 moves left and right within the large valve sleeve 1 according to the change in engine speed, thus changing the X opening and determining the output pressure of P3. When the engine speed drops, the output pressure is controlled by... It can be seen that as the rotational speed decreases, the output flow rate Q of the plunger pump decreases. Since the opening area AO of the throttling shim 3 remains unchanged, and the oil density ρ remains unchanged, the pressure difference Δp after passing through the throttling shim 3 decreases. P1 is the fixed input oil pressure of the gear pump. As Δp decreases, P2 increases. The spring preload remains unchanged, and the right side of the balance equation is greater than the left side. The small valve sleeve 4 moves to the left, and the opening X formed by the small valve sleeve 4 and the large valve sleeve 1 decreases. The oil pressure P3 decreases, and the pilot hydraulic oil pressure supplied to the control handle decreases. Even if the control handle opening remains unchanged, the control oil pressure input to the control variables X1 and X2 ports of the plunger pump decreases accordingly, reducing the output flow rate of the plunger pump.

[0045] The copper sleeve 5 mainly supports the reciprocating motion of the small valve sleeve 4. It is fixed to the small valve sleeve 4 by the retaining ring 6. The initial pre-compression force of the spring 11 can be adjusted by adjusting the screw 13 to calibrate the relationship between the rotational speed and the pressure of P3, facilitating factory-consistent adjustment. The adjusting screw 13 is sealed by two O-rings 16, nuts 17, and nuts 18.

[0046] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any form or substance. It should be noted that those skilled in the art can make various improvements and additions without departing from the present invention, and these improvements and additions should also be considered within the scope of protection of the present invention. Any modifications, alterations, and equivalent changes made by those skilled in the art based on the above-disclosed technical content without departing from the spirit and scope of the present invention are equivalent embodiments of the present invention. Furthermore, any modifications, alterations, and evolutions made to the above embodiments based on the essential technology of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A flameout prevention device, characterized in that, The anti-flameout device is located between the gear pump and the plunger pump control variable mechanism; the anti-flameout device includes a valve body, in which a hydraulic oil inlet and outlet channel is provided. The hydraulic oil inlet end is connected to the gear pump, and the hydraulic oil outlet end is connected to the plunger pump control variable mechanism; the opening of the hydraulic oil outlet end has an automatically variable diameter structure. A fixed cylindrical large valve sleeve is inserted through the valve body; a through hole one for hydraulic oil to flow out is provided on the side wall of the large valve sleeve; a movable cylindrical small valve sleeve is inserted through the large valve sleeve; a through hole two communicating with through hole one is provided on the side wall of the small valve sleeve; through hole one and through hole two form a hydraulic oil outflow opening with variable diameter. The anti-flameout device includes a valve seat connected to a valve body; an adjustment mechanism for adjusting the size of the hydraulic oil outlet opening is provided in the valve seat; the adjustment mechanism includes an adjustment screw passing through the end of a small valve sleeve away from the hydraulic oil inlet of the valve body; an annular throttling washer is provided at the end of the small valve sleeve near the hydraulic oil inlet of the valve body, which is used to establish the relationship between hydraulic oil flow rate and pressure difference through throttling effect, and the flow rate is proportional to the engine speed; The adjusting screw is fitted with a spring and spring seats at both ends of the spring; the spring abuts against the small valve sleeve through the spring seat at one end.

2. The flameout prevention device according to claim 1, characterized in that, The hydraulic oil outlet includes a fixed opening one on the valve body and a movable opening two inside the valve body; the opening one and opening two are connected to form the hydraulic oil outlet, which has an automatically variable diameter structure.

3. The flameout prevention device according to claim 1, characterized in that, The valve body is provided with a valve seat at the end away from the hydraulic oil inlet, and the adjusting screw passes through the valve seat; a fixing nut and a nut are provided in sequence at the end of the adjusting screw away from the small valve sleeve; a locking nut is provided at the end of the adjusting screw close to the small valve sleeve, and a pad is provided between the locking nut and the spring seat.

4. The flameout prevention device according to claim 3, characterized in that, The adjusting screw is connected to the valve seat via a thread; the valve seat is fixedly connected to the valve body.

5. The flameout prevention device according to claim 4, characterized in that, A copper sleeve is provided between the large valve sleeve and the small valve sleeve.

6. The flameout prevention device according to claim 1, characterized in that, The small valve sleeve is provided with a retaining ring that abuts against the spring seat at the end away from the hydraulic oil inlet of the valve body.

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