Portable high-pressure cleaning machine and control method of high-pressure pump

Abstract

The present invention discloses a portable high-pressure cleaning machine and a high-pressure pump control method thereof. The high-pressure cleaning machine using this control method comprises a machine body, a handle, a trigger and a start switch, wherein the start switch is located on the handle and the trigger can operate the start switch. The machine body is equipped with a power supply unit, a motor and a high-pressure pump, and further comprises: a control module, a pressure setting module for presetting the outlet pressure of the high-pressure pump and a pressure detection module for detecting the outlet pressure of the high-pressure pump. The control module adjusts the output power of the motor through the pressure signal provided by the pressure detection module, so that the outlet pressure of the high-pressure pump is maintained at the preset value of the pressure setting module. The present invention eliminates the reduction in efficiency caused by the pressure relief circuit, avoids the reduction in output pressure and flow caused by the reduction in battery pack voltage, and realizes the universal interchangeability of multiple spray guns.

Description

Technical Field

[0001] The invention relates to a portable high-pressure cleaning machine with constant output pressure, and also relates to a control method of a high-pressure pump. Background Art

[0002] In home life and outdoor activities, the demand for cleaning has always been widespread. For closed spaces, people generally use "suction" to clean, such as vacuum cleaners; while for open spaces, people widely use "blowing" to clean, such as hair dryers that use air as the medium and high-pressure cleaners that use water as the medium. Conventional high-pressure cleaners can pressurize, pump and clean tap water during the "blowing" process. Whether it is outdoor activity cleaning or indoor cleaning, there is a strong demand for long working time, large flow and stable high pressure of the cleaning machine.

[0003] Early high-pressure cleaners were generally AC products that used a plunger pump to pressurize the water flow, and the pump body used a pressure relief circuit to release the water flow that exceeded the pressure to maintain a fixed, relatively stable pressure output. However, as we all know, liquids such as water are difficult to compress, that is, once the flow rate changes, when it is greater than the set flow rate, the compressed liquid will flow back to the water inlet circuit through the pressure relief valve, resulting in reduced efficiency; when it is less than the set flow rate, the output pressure drops dramatically and the pressure becomes unstable; and in order to maintain the stability of the output pressure, the flow rate output by this type of high-pressure cleaner is generally much smaller than the flow rate that the pump can provide, which brings about the problem of low pump efficiency.

[0004] Secondly, for AC products, although the voltage and output power are stable, each type of machine needs to adjust the best nozzle according to the flow and pressure of the pump. Under constant flow, if the nozzle is too small, it will be limited by the pressure relief pressure of the pressure relief valve, the reflux ratio will be large, and the efficiency will be low; if the nozzle is too large, the output pressure will be reduced and cannot reach the set value; therefore, the spray guns of AC high-pressure cleaners need to be adjusted according to the flow and pressure settings of the machine, and cannot be used interchangeably, which brings inconvenience to users and wastes social resources.

[0005] With the development of lithium batteries, portable high-pressure cleaners powered by lithium batteries have also appeared in the market. For example, patents CN201380009191.1 and CN201611040688.1 provide an integrated high-pressure cleaner that integrates lithium battery power, DC motor and plunger pump. Its essence is still the result of miniaturization and DC conversion of AC high-pressure cleaners. However, as the battery power decreases, the voltage decreases accordingly, and the motor speed also decreases as the battery pack voltage decreases, further exacerbating the contradiction between the stability of the output pressure and the efficiency of the high-pressure pump.

[0006] The low efficiency of the high-pressure pump not only results in a short battery-powered working time, but also leads to an increase in the volume, weight, and insufficient flow rate of the entire high-pressure cleaner. This is a problem that needs to be solved urgently in the existing technology. Summary of the Invention

[0007] In view of the deficiencies of the existing technology, the technical problem solved by the present invention is to provide a portable high-pressure cleaner and a control method for its high-pressure pump, which can keep the output pressure constant and overcome the defect of low efficiency of the high-pressure pump in the existing technology.

[0008] The portable high-pressure cleaner adopting this control method includes: a body, a handle, a trigger, and a start switch. The start switch is located on the handle, and the trigger can operate the start switch. A power supply unit, a motor, and a high-pressure pump are built into the body. It is characterized by further including: a control module, a pressure setting module for presetting the outlet pressure of the high-pressure pump, and a pressure detection module for detecting the outlet pressure of the high-pressure pump. The control module adjusts the output power of the motor through the pressure signal provided by the pressure detection module to keep the outlet pressure of the high-pressure pump at the preset value of the pressure setting module.

[0009] The control module includes an electronic switch connected to the motor, and an MCU connected to the pressure setting module, the pressure detection module, and the power supply unit. The MCU has a program for performing the following steps:

[0010] 1) The MCU obtains the real-time outlet pressure value of the high-pressure pump through the pressure detection module, denoted as PO, and obtains the preset outlet pressure value of the high-pressure pump through the pressure setting module, denoted as PS;

[0011] 2) If the pressure PO > PS + Of, the electronic switch reduces the PWM to reduce the output power of the motor;

[0012] 3) If the pressure PO < PS + Of, the electronic switch increases the PWM to increase the output power of the motor;

[0013] 4) If PO = PS ± Of, the electronic switch keeps the PWM constant to maintain the output power of the motor; where, Of is the output pressure fluctuation range of the high-pressure pump.

[0014] The high-pressure pump is a diaphragm pump.

[0015] The pressure detection module includes a detection module housing fixed to the high-pressure pump, a single-chip pressure sensor manufactured by MEMS technology, a sealing ring, and a sealant. The sensing detection port of the pressure sensor is communicated with the outlet of the high-pressure pump. The sealing ring is located outside the sensing detection port of the pressure sensor, and the sealant fills the gap outside the sealing ring and inside the detection module housing.

[0016] A one-way valve is connected in series before the inlet of the high-pressure pump.

[0017] The handle is connected to the rear of the body and forms a closed operating ring with the body. The main axis of the handle and the body is arranged at an angle greater than 90 degrees and less than 180 degrees. The trigger is located in the closed operating ring, and the operating surface of the trigger is larger than the gripping surface of the handle.

[0018] It also includes a bracket with a concave upper part and an L-shaped trapezoidal structure at the lower part. The concave part is clamped on the front part of the body. A trigger locking device is provided on the handle, which can lock the trigger position on the handle after the trigger is pressed down.

[0019] The power supply unit is a battery pack located at the lower part of the machine body or an interface connected to an AC power source.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. By measuring the outlet pressure, the motor power is adjusted to maintain a constant outlet pressure, eliminating the inefficiency caused by the pressure relief circuit; 2. The solution of maintaining a constant outlet pressure of the present invention also avoids the reduction of output pressure and flow caused by the reduction of battery pack voltage; 3. For AC products, within the caliber required for the maximum flow, regardless of the size of the nozzle outlet, the outlet pressure can be adjusted and constant with high efficiency, without adjusting the nozzle caliber according to the parameters of the high-pressure cleaning machine, and realizing the universal interchangeability of multiple spray guns. 4. The output pressure can be adjusted through the pressure setting module to achieve a wide range of applications, realizing the multi-functions of handheld high-pressure cleaning, portable water pumping and drainage, and pressurization. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural schematic diagram of the portable high-pressure cleaning machine of the present invention.

[0022] Figure 2 It is the electrical schematic diagram of the control module of the present invention.

[0023] Figure 3 It is a control logic schematic diagram of the present invention.

[0024] Figure 4 It is a structural diagram of the pressure detection module.

[0025] Figure 5 yes Figure 4 Magnified image of .

[0026] Figure 6 It is a structural schematic diagram of another embodiment of the present invention.

[0027] Figure 7 yes Figure 6 AA section view.

[0028] The reference numerals shown in the figure are as follows: 1-compression pump 2-motor 3-body 4-pressure setting module 5-start switch 6-water inlet pipe 7-handle 8-trigger 9-locking device 10-check valve 11-water inlet interface 12-battery pack 13-control board 14-water outlet pipe 15-water outlet interface 16-pressure detection module 17-external water pipe 18-hose interface 19-bracket 20-pressure detection port 21-compression pump outlet 22-compression pump inlet 31-pressure sensor 30-sensing detection port 32-PCB board 33-sealant 34-sensing module housing 35-sealing ring 40-MCU unit 4-pressure setting module 41-electronic switch DETAILED DESCRIPTION

[0029] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0030] Figure 1 The figure is a schematic diagram of the structure of the portable high-pressure cleaning machine of the present invention, including a body 3, a handle 7 for convenient hand-held operation, a trigger 8 for turning the machine on and off, a motor 2, a compression pump 1, a pressure detection module 16, a control board 13 and a battery pack 12 are arranged inside the body 3, and the body 3 also includes a water inlet interface 11, a water outlet interface 15 and a pressure setting module 4, the water inlet interface 11 is connected to an external water pipe, and the external water is sent to the compression pump 1 through the water inlet pipe 6 for compression, and then sent out through the water outlet pipe 14 and the water outlet interface 15; the water outlet interface 15 can be connected to various water guns, hoses and spray guns.

[0031] Among them, the compression pump 1 can be effective whether it is a plunger pump, a diaphragm pump or other variable volume pump as long as there is no pressure relief circuit or the pressure relief circuit setting value is greater than the preset value of the control board 13. Considering that the plunger pump has many dynamic seals and the resistance of the dynamic seals is large, resulting in a relatively low efficiency of the compression pump, the present invention preferably uses a diaphragm pump, which optimizes the one-way valve core and has an air suction vacuum greater than 30KPA.

[0032] The motor 2 provides power for the compression pump 1 and may be a DC motor, a series motor, an induction motor, a brushless motor, a synchronous motor or any other converter that converts electrical energy into mechanical energy.

[0033] See also Figure 2 , Figure 3, on the control board 13, there is an MCU unit 40 and an electronic switch 41. The control board 13 selects different control circuits that can adjust the output power of the motor 2 according to different motors 2. The control board 13 is responsible for comparing the preset pressure value with the detected pressure value and adjusting the output power of the motor 2, so as to achieve the goal of keeping the output pressure of the compression pump 1 constant. The MCU unit 40 is connected to the battery pack 12, the electronic switch 41, the pressure detection module 16 and the pressure setting module 4. The battery pack 12 (which can also be an interface for connecting to an AC power supply) provides electrical energy for the entire system. Specifically, the battery pack 12 provides a DC working power supply for the MCU unit 40 and the pressure detection module 16, and also provides a drive control power supply for the electronic switch 41. The MCU unit 40 has a built-in program, and this program can execute the following steps:

[0034] 1: After power-on, the MCU unit detects the signal of the pressure detection module and obtains the outlet pressure PO of the compression pump;

[0035] 2: The MCU unit compares the obtained pressure value PO with the set pressure value PS of the pressure setting module;

[0036] 3: If the pressure PO > PS + Of, the MCU unit adjusts the PWM of the control pole of the electronic switch unit to reduce the output power of the motor;

[0037] 4: If the pressure PO < PS + Of, the MCU unit adjusts the PWM of the control pole of the electronic switch unit to increase the output power of the motor;

[0038] 5: If PO = PS ± Of, the MCU unit maintains the PWM of the control pole of the electronic switch unit to maintain the output power of the motor;

[0039] Among them, Of is the output pressure fluctuation range of the high-pressure pump.

[0040] This pump unit and its control method are very suitable for battery-powered handheld high-pressure cleaners that require high efficiency and voltage variation.

[0041] The function of the pressure detection module 16 is to detect the output pressure of the compression pump 1 and transmit the pressure signal to the control board 13. Conventional sensors that can detect liquid pressure are not only large in size but also very costly, with a selling price of over a thousand yuan. This is one of the reasons why pressure control is not generally adopted in the pump units of household high-pressure cleaners. The present invention provides a low-cost liquid pressure detection module 16. Such as Figure 4 、 Figure 5As shown: the present invention adopts a single-chip liquid pressure sensor manufactured by MEMS technology, which has the advantages of small size and low cost, but also has the characteristics of small size and difficulty in sealing. The present invention provides a low-cost and reliable sealing method: a pressure detection port 20 is provided on the pump body of the compression pump 1, and the pressure detection port 20 is a very small hole with a diameter of no more than 2mm, and is connected to the outlet 21 of the compression pump 1; the pressure sensor 31 is welded on the PCB board 32, and the PCB board 32 is fixed inside the sensor module housing 34, and the signal line passes through the sensor module housing 34 and is connected to the control board 13; the pressure sensor 31 has a sensing detection port connected to the pressure detection port 20; the gap between the place outside the sensing detection port 31 and the sensing module housing 34 is filled with sealant 33 for sealing; considering the sealing process to prevent the sealant 33 from clogging the sensing detection port 31, a sealing ring 35 is added between the sensing detection port 31 and the pressure detection port 20 to prevent the sealant 33 from dipping into the detection channel; the sensor module housing 34 is fixed on the housing of the compression pump 1.

[0042] Since the pressure sensor 31 outputs a corresponding analog value according to the pressure value, the control board 13 is required to compare the analog value with the set value and control the power of the motor 2. The control board 13 needs to be further explained. This implementation example is a control board for a DC motor, which does not mean that this solution is only applicable to DC motors. For AC motors, it only needs to use corresponding control circuits for controlling the motor speed, power or torque.

[0043] The pressure setting module 4 can set the output pressure of the water outlet pipe 14. Since portable high-pressure cleaners are divided into two categories according to their uses: high-pressure cleaning and pressurization, high-pressure cleaning requires a large output pressure to obtain a high water outlet speed; while pressurization is to extract and pressurize the external low-pressure tap water, river, and pond water for irrigation and transportation; therefore, the pressure setting module 4 sets the pressurization gear and the cleaning gear; at least two pressure settings are included, one set pressure is not greater than 0.6MPa; the other pressure setting is not less than 1.5MPa. Multiple pressure gears can also be set.

[0044] The operation process is as follows: connect the water pipe to the external water source, and connect the water pipe to the water inlet interface 11; connect the water outlet interface 15 to a spray gun, a nozzle or other water gun; press the trigger 8, the trigger 8 presses the micro switch 5, and the control board 13 is powered on and started; set the output pressure on the pressure setting module 4; the control board 13 simultaneously turns on the electronic switch 43 to start the motor 2 and drive the compression pump 1 to work; the control board 13 detects the pressure value of the pressure detection module 16 and compares it with the pressure value set on the pressure setting module 4; adjusts the power output of the motor 2 according to the comparison result to maintain the output pressure consistent with the set pressure.

[0045] Considering that the water inlet pipe is separated from the water inlet interface 11 after the high-pressure cleaning machine is turned off, on the one hand, it is necessary to prevent water from flowing out of the water inlet interface 11 and causing pollution, and on the other hand, it is necessary to store some water in the pump for quick emptying the next time it is used. Common similar products use a valve linked to a trigger to close the channel of the water inlet pipe 6; however, this structure is complex and the reliability of the dynamic seal is relatively poor, which can easily lead to seal failure and inability to self-prime. The present invention uses a one-way valve 10 in series in the water inlet pipe 6 between the compression pump inlet 22 and the water inlet interface 11, so that water can only flow in one direction.

[0046] Considering that the most common use scenario of portable high-pressure cleaners is handheld, the convenience of one-handed operation must be considered. Based on the user experience and sense of balance, the present invention has the following considerations for the structural layout of the high-pressure cleaner: the water inlet interface 11 and the water outlet interface 15 are arranged at an angle greater than 90 degrees and less than 180 degrees on the body 3, and the water inlet interface 11 is located at the rear lower part of the handle 7, so that the water inlet pipe does not interfere with the movement during operation. The handle 7 and the axis of the body 3 are arranged at an angle greater than 90 degrees and less than 180 degrees; the handle 7 is located at the rear of the body 3 and connected to the body 3 to form a closed operating ring; the trigger 8 is located in the closed operating ring; the start switch 5 is located on the upper part of the handle and the trigger 8 can operate the start switch 5; the pressure setting module 4 is located on the body or the handle, so that the thumb can easily operate while holding the trigger 8; the operating surface of the trigger 8 is larger than the gripping surface of the handle 7, and the upper rear part of the body 3 can also be operated. This structure is convenient for both hand-held and placed operations. The battery pack 12 is located below the body 3 and close to the water inlet port 11 for the purpose of balancing the center of gravity.

[0047] The handheld structure does not allow the high pressure cleaner to be placed stably on the ground. Figure 6~Figure 7 The present invention also provides a bracket 19, the upper part of which is concave and the lower part is an L-shaped trapezoidal structure; the concave part can clamp the front part of the machine body to keep the machine body upright with the support surface. The present invention is provided with a locking device 9 on the trigger, and the trigger 8 is pulled to start the machine, and the trigger 8 is fixed with the locking device 9 to maintain the machine started state. The high-pressure cleaning machine is placed on the bracket to maintain the stability of the placement state. The water outlet interface of the high-pressure cleaning machine is connected to a hose interface 18, and the external water source is connected to the water inlet interface 11 through the water pipe 17, so that it can be used as a delivery pump to extract water and transport it to other places.

Claims

1. A portable high-pressure cleaning machine, comprising: A body, a handle, a trigger and a starting switch, the starting switch is located on the handle, and the trigger can operate the starting switch. A power supply unit, a motor and a high-pressure pump are built in the body. It is characterized by further comprising: a control module, a pressure setting module for presetting the outlet pressure of the high-pressure pump, and a pressure detection module for detecting the outlet pressure of the high-pressure pump. The control module adjusts the output power of the motor through the pressure signal provided by the pressure detection module to keep the outlet pressure of the high-pressure pump at the preset value of the pressure setting module. The control module includes an electronic switch connected to the motor, and an MCU connected to the pressure setting module, the pressure detection module and the power supply unit. The MCU has a program for performing the following steps: 1) The MCU obtains the real-time outlet pressure value of the high-pressure pump through the pressure detection module, denoted as PO, and obtains the preset outlet pressure value of the high-pressure pump through the pressure setting module, denoted as PS; 2) If the pressure PO > PS + Of, the electronic switch reduces the PWM to reduce the output power of the motor; 3) If the pressure PO < PS + Of, the electronic switch increases the PWM to increase the output power of the motor; 4) If PO = PS ± Of, the electronic switch keeps the PWM constant to maintain the output power of the motor; where, Of is the output pressure fluctuation range of the high-pressure pump; The pressure detection module includes a detection module housing fixed to the high-pressure pump, a single-chip pressure sensor manufactured by MEMS technology, a sealing ring and a sealant. The sensing detection port of the pressure sensor communicates with the outlet of the high-pressure pump. The sealing ring is located outside the sensing detection port of the pressure sensor. The sealant fills the gap outside the sealing ring and inside the detection module housing.

2. The portable high-pressure cleaning machine according to claim 1, characterized in that: The high-pressure pump is a diaphragm pump.

3. The portable high pressure cleaning machine according to claim 1, characterized in that: A check valve is connected in series before the inlet of the high-pressure pump.

4. The portable high pressure cleaning machine according to claim 1, characterized in that: The handle is connected to the rear of the body and forms a closed operation loop with the body. The main axis of the handle and the body is arranged at an angle greater than 90 degrees and less than 180 degrees. The trigger is located within the closed operation loop, and the operating surface of the trigger is larger than the握持 surface of the handle.

5. The portable high pressure cleaning machine according to claim 1, characterized in that: It further includes a bracket with a trapezoidal structure that is concave at the upper part and L-shaped at the lower part. The concave part of the concave shape catches the front part of the body. A trigger locking device is provided on the handle, which can lock the position of the trigger on the handle after the trigger is pulled down.

6. The portable high-pressure cleaning machine according to any one of claims 1 to 5, characterized in that: The power supply unit is a battery pack located at the lower part of the body or / and an interface connected to the AC power supply.

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