DE2018112A1 - - Google Patents

Description

PATENT LAWYERS 2018 112 Dipi.-chem. Dr. D. Thomsen Di _P i.-ing. H. TSedtke
Dipi.-chem. G. Boehling MUNICH 2
VAL 33
TEL. 0311/226394
295051
CABLES: THOPATENT
TELEX: TO FOLLOW Dipi-ing. W.Weinkauff FRANKFURT (MAIN) 5 <
FUCHSHOHL 71
TEL. 0611/514566

Answer requested to:

Please reply to: '

8000 Munich 2 April 15, 1970 case 2O49 / T3559

Nippondenso Kabushiki Kaisha

Kariya-shi, Japan

and
Toyota Jidosha Kogyo Kabushiki Kaisha.

Toyota-shi, Japan

Piston pump with controlled flow rate

The invention relates to a pump device with a piston, a cylinder and an electromagnetic valve through which the fluid for control the flow rate of the pump is measured electrically.

In conventional piston pumps, the pump throughput is controlled by supporting the lower end of a connecting rod connected to the piston with the aid of a lever device consisting of a stopper or the like, changing the position of the stopper using the lever principle to achieve the return stroke limit the piston. Such a construction has the disadvantage that.

00 9 84 9/126 6

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by using lever devices the mechanical "Building is very complicated.

Aufgäbe.der invention is the throughput of fluids to control by the pump in a simple manner that one. only depending on the desired Flow rate an electromagnetic valve opens or closes.

■ This object is achieved in a pump with a piston and a cylinder in that in a fluid inlet channel, which is in communication with a pressure chamber formed between the piston and the cylinder, an electromagnetic valve is provided which is normally used for constant supply of fluid to the pressure or pressure Compression chamber is held in its open state and closed when the volume of the pressure chamber is on the upstroke of the piston to one of the desired flow rates corresponding value has been narrowed, whereby the fluid limited and measured in the pressure chamber.

The invention is explained below with reference to a schematic drawing which is a view of the pump control device and shows an embodiment of a pump device according to the invention with controlled throughput.

The reference number 1 denotes a camshaft for 009849/1268

the pump drive, on which a cam 2 is firmly seated. The cam 2 is in contact with a push rod 3 which is biased by a return spring 3 '. Reference numeral 4 denotes a piston with a fluid channel 5 formed therein which determines the end of the fluid discharge process of the piston. The piston 4 is seated so that it can move back and forth in a cylinder 6 and is connected at its lower end to the molded bumper 3. The reference number 7 denotes a pressure chamber or compression chamber in which the measurement and compression of the fluid are effected. The reference number 8 denotes a throttle. Numeral 10 denotes an electromagnetic valve; 11 is a return spring that exerts a return movement on a valve lifter 13; 12 is a valve seat on which the valve stem 13 is seated in the excited state of the electromagnetic valve to stop the flow of the fluid; 14 is a fluid passage in the valve lifter 13. Reference numeral 15 denotes a dispensing valve which is set to dispense fluid at an optimal dispensing pressure. Reference numeral 16 denotes a fluid tank which is connected to the throttle 8 via one line and to the electromagnetic valve 10 via another line via a delivery pump 17. Reference numeral denotes a controller which controls the electromagnetic valve 10 by a signal from a timer 19 which ^{generates the} signal in synchronism with the rotation of the driving camshaft.

009849/1266

The device according to the invention, designed in the prescribed manner, works in the following way: If the camshaft 1 is rotated in the direction of the arrow a, the push rod, which is in working contact with the cam 2, is moved in the direction of the arrow b, whereby the piston moves upwards and the fluid is compressed. During this perlode, the electromagnetic valve is kept in its de-energized state, the valve stem 13 being held at a distance from the valve seat 12 under the action of the return spring 11, so that the fluid through the feed pump 17 from the fluid tank 16 in the direction indicated by the arrow c The fluid passing through the fluid channel 14 of the electromagnetic valve 10 enters the pressure chamber 7 through an inlet channel 9 and fills this chamber _9, with excess fluid flowing through the throttle 8 according to arrow d to a tank 1β. If the piston 4 rises further at _a , the throttle 8 is completely closed by the side wall of the piston 4, after which the fluid pressure in the pressure chamber 7 is built up by the rising piston 4. As long as the fluid pressure in the pressure chamber 7 is lower than the valve opening pressure of the dispensing valve 15, the fluid in the chamber flows according to arrow e over the electromagnetic valve 30 out and v ^ nrt under

0-9849 / 1266

BATH

. ■■■ '..- 5 - ·

Bypassing the feed pump 17 back into the tank 16 through a pressure regulating valve arranged in the pump, the pressure regulating valve being set so that it opens at a pressure * which is less than that of the dispensing valve 15. If the volume of the pressure chamber 7 is reduced to a fourth, which corresponds to the amount of fluid that is to be dispensed with further upward movement of the piston 4, the electromagnetic valve 10 is excited by the control device 18, which receives a signal from the timing element 19, so that the valve tappet 13 sits tightly on the valve seat 12 and blocks the fluid passage, whereby the fluid is enclosed in the pressure chamber 7 and thereby measured. If the piston 4 rises further, the fluid pressure overcomes the valve opening pressure of the dispensing valve 15, so that the fluid measured in this way is dispensed in the direction of the arrow g through the dispensing valve. As the discharge progresses and the piston ¹ J continues to rise, the fluid channel 5 in the piston 4 is brought into communication with the throttle 8, so that the fluid enclosed in the pressure chamber 7 is released to the outside in the direction of arrow d. This reduces the fluid pressure in the pressure chamber and the fluid delivery inevitably ends. ·. The end of the flow agent delivery process can be kept constant. From the above it follows that by electrically determining the time at which the

W9849 / 1266

Electromagnetic valve 10 is closed and "■ the" valve stem 13 is in close contact with the valve seat 12 is located, it is possible to precisely control the flow rate of the fluid.

In the prescribed embodiment of the invention is provided through the fluid channel 5 provided in the piston 4 and "the one provided on the cylinder · β Throttle 8 the end of the fluid dispensing process of the , Piston · 4 reaches before the piston reaches its top dead center reaches j of course, the end "of the fluid dispensing process can also be set so that that it is reached when the piston 4 is at its top dead center.

According to the invention to be dispensed from a 'piston pump StrömungSjnittelmenge <} _a d _Urc h is measured, that is connected in the fluid inlet channel 9, the pressure chamber 7 formed with the ^ between the piston Kund the cylinder S, arranges the electromagnetic valve 10, which is normally in its open state is kept in order to achieve a constant supply of the fluid into the pressure chamber, the valve being closed when the volume of the pressure chamber on the upward stroke of the piston 4 has been reduced to a value that corresponds to the desired delivery or throughput amount of the fluid · corresponds to the fluid

'Enclose and measure in the pressure chamber. In the

009849/1266

The device according to the invention, it is only necessary, depending on the desired throughput rate, to keep the electromagnetic valve in the open state or in the closed state ¹¹ ; in contrast, in the conventional flow control devices, the end of the return stroke of the piston is fixed mechanically. Accordingly, the invention has a great advantage that an electrically controlled flow rate pump device can be obtained with a very simple structure.

0098A9 / 1266

Claims (3)

Claims Pump device with controlled throughput, characterized by a piston, a cylinder and a Electromagnetic valve (10) in a fluid inlet port (9) is provided - the one formed between the piston (4 ") and the cylinder (6) Pressure chamber (7). Is in communication, the electromagnetic valve (10) to achieve a constant Supply of fluid into the pressure chamber (7) is normally held in an open state and closed is when, on the upward stroke of the piston (4), the volume in the pressure chamber (7) is reduced to a fourth has been, which corresponds to a desired fluid flow rate, whereby the fluid in the pressure chamber is limited and measured. 2. Pump device according to claim 1, characterized in that that the cylinder (6-) has a dispensing valve (15), the fluid at an optimal dispensing pressure releases, as well as a throttle (8), through the excess Fluid flows to the outside of the cylinder. 3. Pump device according to claim 2, characterized in that the piston (H) has a fluid channel ΌΌ98Α9 / 126 6 ■■ -. (5), which can be brought into connection with the throttle (8) when the piston rises. 009849 / 126-6 ? 0 Blank page