JP4796026B2 - Pressure control device in oil pump - Google Patents

Description

  The present invention has a plurality of discharge sources, and the pressure in an oil pump that can reduce friction while maintaining the same characteristics as the pressure characteristics of a general oil pump by devising an oil path switching method. The present invention relates to a control device.

As a conventional technique, there is a variable flow rate oil pump, and there are two discharge ports because one discharge port is divided into two. However, considering a discharge source, it remains one because it is a set of rotors. Further, the oil passages of the main pump (first pump) and the sub pump (second pump) are in communication with each other during high rotation with high power consumption of the pump. Therefore, the pressures of the main pump and the sub pump are substantially equal. Although it is expressed as a main pump and a sub pump, it is originally one pump (a set of rotors), and even if there is a wasteful work, a single set of pumps cannot reduce much. Furthermore, since the discharge path of the sub pump ends in the valve, there is a limit to the flow rate adjustment using only the valve.
JP2005-140022 JP 2002-70756 A

  Patent Document 1 aims at reducing unnecessary work and improving efficiency in the rotational speed range by relieving (returning) oil in a desired rotational speed range. As shown in FIG. 8 on page 13, by reducing the flow rate in the desired rotational speed range, unnecessary work is reduced and efficiency is increased. However, since the sub pump is relieved while communicating with the main pump even at high speed rotation, there are the following problems. The sub pump does the work (discharge) that generates the same pressure as the main pump, and there is a limit to the reduction of wasted work.

  The valve is adjusted to reduce unnecessary work, but the main and sub flow (pressure) fluctuations as a result of adjusting the relief position of the valve are all directly connected to the flow (pressure) fluctuation of the pump as a whole. Since the inflection points of the sub flow rate are shifted and overlapped, there are a large number of steep inflection points in the overall flow rate (pressure) of the pump, and vibrations are generated by the many steep points, increasing the burden on the piping and noise.

  In addition, since the flow rate (pressure) variation due to the valve is directly connected to the flow rate (pressure) variation of the entire pump, variations in pump performance will occur unless manufactured with a considerably high dimensional accuracy. Since the characteristics do not change in a straight line but in a staircase, the effect of variation is more conspicuous. Further, since the discharge oil passage of the sub pump passes through the valve and is immediately connected to the main pump, there is a limit in changing the flow rate (pressure) of the sub pump only by the valve.

  Therefore, as a problem to be solved by the present invention (technical problem or object), a pressure characteristic of a general oil pump (cited document 2) is provided by having a plurality of discharge sources and devising an oil passage switching method. 10 has a non-step-like characteristic passing through the dotted line in Fig. 10 on page 7. The valve has only a function of relief ON and OFF, and has only one inflection point of the characteristic. ) To achieve a reduction in friction while maintaining substantially the same characteristics as in FIG.

  In view of this, the inventor has intensively and researched to solve the above problems, and as a result, the invention of claim 1 includes a first discharge passage for feeding oil from the first set rotor to the engine, and the first set rotor. A first return path that returns to the suction path, a second discharge path that feeds oil from the second set rotor to the engine, a second return path that returns to the suction path of the second set rotor, and a first valve A valve body comprising a portion, a small diameter connecting portion, and a second valve portion comprises a pressure control valve provided between a discharge port from the second set rotor and the first discharge passage, and the first The discharge path and the second discharge path are connected, only the first discharge path and the second discharge path are opened and communicated with the low rotation range, and the first discharge path is connected with the middle rotation range. And the two discharge paths are opened and communicated, the first return path is closed and the second return path is opened, In the high rotation range, the second discharge path is closed and the first discharge path is opened, so that communication is lost, and the first return path and the second return path are opened, The above problems have been solved by using a pressure control device in an oil pump that is controlled in flow path.

  According to a second aspect of the present invention, there is provided a pressure control device in an oil pump, characterized in that, in the above-described configuration, each of the first set rotor and the second set rotor is a separate oil pump. The above-mentioned problem has been solved. According to a third aspect of the present invention, in the above-described configuration, the first set rotor and the second set rotor are configured as one oil pump having three or more rotors. Thus, the above-mentioned problem is solved.

  In the first aspect of the invention, during the high speed rotation, the second discharge passage of the second set rotor is completely closed, the second set rotor becomes an independent circuit, and the second set rotor has a useless work pressure. Even if it is not generated, it is possible to obtain an effect that the overall pressure of the pump does not decrease. Further, since work = pressure × flow rate, it is possible to reduce unnecessary work if the pressure is reduced. When the first discharge path of the first set rotor and the second discharge path of the second set rotor communicate with each other as in the prior art, the pressure of the second set rotor is the return path pressure of the first set rotor. It does n’t go down below. In the present invention, since the second set rotor is an independent circuit at high speed rotation, if the opening area of the return path of the second set rotor is increased, more layer oil is discharged and the pressure of the second set rotor is increased. Can be further reduced. Further, since the second discharge passage of the second set rotor is fully closed when the second set rotor is rotating at high speed, only the flow rate (pressure) of the first set rotor affects the flow rate (pressure) of the entire pump. It becomes.

  In addition, since the flow rate (pressure) of the second set rotor is not visible on the surface during high-speed rotation, the pump as a whole is not affected, and the characteristics change from a stepped shape to a linear shape, which is a problem with variable flow rate pumps. There is no need to tighten the dimensional accuracy more than ever. Since the first set rotor and the second set rotor are separate discharge sources and are separate discharge passages up to the valve, two valves can be controlled more accurately by the valve (communication before the valve). The valve control is limited. In addition, since the second discharge path of the second set rotor extends to the downstream side of the valve, the second set rotor is more susceptible to valve opening and closing, and the flow rate (pressure) of the second set rotor is controlled by the valve. Is easy to change. In addition, since there are two sets of discharge sources, it is possible to reduce the work amount of the rotor on one side and further reduce waste work.

  In the invention of claim 2, since each of the first set rotor and the second set rotor is a separate oil pump, vibration, noise, discharge pulsation, etc. are canceled out by two pumps and reduced. be able to. Furthermore, in the invention of claim 3, the first set rotor and the second set rotor are made into one oil pump having three or more rotors, so that a reduction in space, weight, and number of parts can be achieved. .

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in FIGS. 1 to 3, A is a first set rotor and B is a second set rotor. The outer rotor, the inner rotor, the discharge port, the suction port, and the like. A first discharge path 1 for feeding oil to the engine E, a first return path 2 for returning to the suction path 8 of the first set rotor A, a second discharge path 3 for feeding oil to the engine E, and the second The second return path 4 returns to the suction path 9 of the assembly rotor B, and an appropriate position in the middle of the first discharge path 1 is connected to the end portion side of the second discharge path 3. The first set rotor A and the second set rotor B of the first embodiment are respectively separate oil pumps. As shown in FIG. 1, the first set rotor A serving as an oil pump includes an outer rotor 111, The inner rotor 112, the discharge port 113, and the suction port 114 are configured. The second rotor set B, which is an oil pump, includes an outer rotor 122, an inner rotor 121, a discharge port 123, and a suction port 124. Reference numerals 115 and 125 denote drive shafts.

  Further, the valve body 5 including the first valve portion 51, the small diameter connecting portion 53, and the second valve portion 52 includes the first discharge path 1, the first return path 2, the second discharge path 3, and the second return path 4. A pressure control valve C is provided at an appropriate position of the valve housing 10 therebetween. The pressure control valve C is formed with a slot 11 that is slidable in the valve body 5 as appropriate, and is fixed to the rear side of the second valve section 52 of the valve body 5 in the slot 11. The lid 7 is constantly pressed toward the first valve portion 51 by the elastic force of the compression coil spring 6. Reference numeral 12 denotes a stop step portion which is located at an appropriate position in the first discharge path 1 and is formed at the end of the elongated hole portion 11.

  The control of the pressure control valve C includes various items that determine the pressure state, the diameter of the valve body 5, the spring constant of the compression coil spring 6, etc., but depending on the change in the discharge pressure of the first discharge path 1, etc. However, it is necessary to satisfy various conditions. Specifically, as shown in FIG. 1, only the first discharge path 1 and the second discharge path 3 are opened in the low rotation range, and in the middle rotation range, as shown in FIG. The first discharge path 1 and the second discharge path 3 are opened, the first return path 2 is closed, and the second return path 4 is opened. Thus, the second discharge path 3 is closed, the first discharge path 1 is opened, and the first return path 2 and the second return path 4 need to be controlled in the opened state.

  Next, the operation of the pressure control valve C will be described. First, when the first group rotor A and the second group rotor B are in the low rotation range, that is, when the engine speed is in the low rotation range, the state shown in FIG. The return path of the assembly rotor B is also blocked by the first valve portion 51 and the second valve portion 52 of the pressure control valve C, and all the oil discharged from the first discharge passage 1 and the second discharge passage 3 is sent to the engine. Discharged. Since the first discharge path 1 of the first set rotor A and the second discharge path 3 of the second set rotor B are in communication, the pressures are equal. Further, since the return path is blocked, the discharge flow rate of the entire oil pump is the sum of the flow rates of the first set rotor A and the second set rotor B. This is a low rotation range in the characteristic table of the rotational speed and the discharge pressure [see FIG. 5A] or the characteristic table of the rotational speed and the discharge flow rate [see FIG. 5B].

  Furthermore, let the state which the rotation speed of the engine rose be a middle rotation area. In this state, the opening 41 of the second return path 4 starts to open, and the opening 31 of the second discharge path 3 starts to close, as shown in FIG. This will be specifically described. The first discharge path 1 of the first set rotor A and the second discharge path 3 of the second set rotor B remain in communication. Since the opening of the opening 41 of the second return path 4 of the second set rotor B is started, the pressure increase of the second set rotor B first stops. At the same time, since the first discharge path 1 and the second discharge path 3 are in communication with each other, the oil flows backward from the discharge of the first set rotor A to the discharge side of the second set rotor B, and the second set rotor B is left as it is. It is discharged from the second return path 4 and returns to the suction path 9 of the second rotor B. By this series of action states, the pressures of the first set rotor A discharge and the second set rotor B discharge become substantially equal.

  As the rotational speed increases in the middle rotation range, the opening 31 of the second discharge path 3 of the second set rotor B gradually closes, and the opening 41 of the second return path 4 of the second set rotor B opens. Since it gradually opens, the overall flow rate hardly increases even if the rotation speed increases. The pressure that does not appear on the true surface of the discharge of the second set rotor B gradually decreases because the opening 41 of the second return path 4 of the second set rotor B gradually opens. However, since the first discharge path 1 and the second discharge path 3 communicate with each other, the pressures of the first group rotor A and the second group rotor B are equal, and the pressure of the second group rotor B is the surface. The top does not go down.

  In addition, since the opening 21 of the first return path 2 is not yet opened in the middle rotation range, the discharge flow rate of the first set rotor A increases with the rotation speed. The discharge flow rate of the second set rotor B decreases with the rotational speed because the opening 41 of the second return path 4 of the second set rotor B opens. Since the reverse flow rate from the discharge of the first set rotor A exceeds the discharge flow rate of the second set rotor B at a certain number of revolutions or more, the discharge flow rate of the second set rotor B is subtracted minus. . Since it can be negative in this way, the total flow rate of the oil pump can be the total flow rate of the two pumps, or the flow rate can be less than one pump. Widely variable.

  If an orifice 32 (passage with reduced flow cross-sectional area) is provided in the middle of the second discharge passage 3 of the second set rotor B as required, pressure loss occurs at the 32 orifice locations, The discharge pressure of the second set rotor B decreases. Then, after passing through the orifice 32, the pressure is equalized in communication with the discharge of the first set of rotors A. That is, the discharge pressure of the second set rotor B before passing through the orifice 32 is slightly higher than the discharge pressure of the first set rotor A. For this reason, the discharge pressure of the initial second set rotor B in the middle rotation range is slightly higher than the discharge pressure of the first set rotor. However, the opening area of the opening 41 of the second return path 4 of the second set rotor B increases, so that the oil flows back from the discharge of the first set rotor A to the discharge side of the second set rotor B. Then, the effect of the orifice 32 is lost, and the discharge pressure of the second set rotor B and the discharge pressure of the first set rotor A become equal. This middle rotation region appears in the pressure characteristic table (see FIG. 5) of the rotation speed and the discharge pressure or the discharge flow rate, and the first set rotor A increases monotonously, but the second set rotor B side has a reverse flow. Thus, the total pressure connecting line of the first set rotor A and the second set rotor B can be made substantially the same as the pressure characteristic of the conventional oil pump.

  Furthermore, the state in which the engine speed has increased is defined as a high engine speed range. In this state, it is the state of FIG. 3 or 4, and the opening of the opening 21 of the first return path 2 starts and the closing of the opening 31 of the second discharge path 3 ends. This will be specifically described. Since the discharge of the second set rotor B is completely closed, there is no communication between the discharge of the first set rotor A and the discharge of the second set rotor B. That is, the second set rotor B is an oil circuit independent of the first set rotor A. The pressure from the discharge of the first set rotor A cannot reach the second set rotor B, and is only returned from the second return path 4 of the second set rotor B. The pressure drops all at once. The reverse flow to the second set rotor B is also stopped, and all the oil discharged from the second set rotor B is returned via the second return path 4, so that the second set rotor B returns to the engine E. The flow rate becomes zero. In other words, the flow rate of the second set rotor B becomes zero, and the discharge of the second set rotor B does not work at all, so the friction (torque) is reduced at a stretch and unnecessary work can be reduced, so the efficiency of the entire pump increases. To do. This high rotation range appears in the pressure characteristic table (see FIG. 5) of the rotational speed and the discharge pressure or the discharge flow rate, and the first set rotor A rises slowly, but the second set rotor B is in the closed state. Yes, the total pressure connection line of the first set rotor A and the second set rotor B is only the first set rotor A. Thus, since the pressure of the 2nd group rotor B falls, since friction (torque) reduces, efficiency rises.

  Regarding the pressure of the first rotor A, the oil is returned through the second return path 4 because the first discharge path 1 and the second discharge path 3 are in communication in the middle rotation range. In the high rotation range, since the feedback is continued from the first return path 2, the pressure of the first set rotor hardly changes in the middle rotation range or the high rotation range. Further, the flow rate of the first set of rotors A does not change much after the flow rate has once decreased because the opening 21 of the first return path 2 opens and flows into the first return path 2 at the moment of opening. Strictly speaking, it increases slightly as the rotational speed increases.

  The "pressure" as the whole pump (the total of the first group rotor A and the second group rotor B) is because the opening 31 of the second discharge passage 3 of the second group rotor B is completely closed. It becomes the pressure of only the first set rotor A. The pressure of the first rotor A does not change much because the opening 21 of the first return path 2 is open, but strictly speaking, it increases little by little as the rotational speed increases. Moreover, since the opening 31 of the second discharge passage 3 of the second set rotor B is completely closed, the “flow rate” of the first set rotor A is the total flow rate of the pump. Become. The flow rate of the first set rotor A does not change much because the opening 21 of the first return path 2 is open, but strictly speaking, it increases little by little as the rotational speed increases.

  As described above, the present invention is a pressure control device in an oil pump, but is also a variable flow rate oil pump. There are two discharge paths, and the discharge source uses two sets of rotors (double rotor or three or more rotors). Further, since the discharge port 30 or the second discharge path 3 of the second set rotor B is closed at the time of high rotation with high power consumption of the pump, the first set rotor A and the second set rotor B are separated. . Since the flow rate and pressure of the second set rotor B do not affect the flow rate and pressure of the entire pump, even if the flow rate and pressure of the second set rotor B are adjusted to improve efficiency, the pump characteristics Does not have any influence, so the degree of freedom in design increases. Also, if the two discharge sources are separate pumps, it is possible to drastically reduce the wasteful work of one pump on one side at high revolutions. Further, since the second discharge path 3 of the second set rotor B extends to the downstream side of the pressure control valve C, the flow rate adjustment by the pressure control valve C is easy.

  Moreover, the 1st group rotor A and the 2nd group rotor B of 2nd Embodiment are one oil pump of three or more rotors. Specifically, as shown in FIG. 6, the first rotor A is composed of an outer rotor 131, an intermediate rotor 132, a discharge port 134 and a suction port 135. The second rotor set B includes an intermediate rotor 132, an inner rotor 133, a discharge port 136, and a suction port 137. That is, one oil pump including the first set rotor A and the second set rotor B by three rotors is configured. The configurations of the discharge passages, the return passages, and the pressure control valve C as pressure control devices in the first set rotor A and the second set rotor B of the second embodiment are the same as those in the first embodiment. Therefore, the operation of the second embodiment is the same as that of the first embodiment, as shown in FIGS. Therefore, the description thereof is omitted. Further, the effects are also equivalent, and the description is omitted. FIG. 6 is a state diagram when the engine speed is in a low speed range.

  Moreover, the 1st group rotor A and the 2nd group rotor B of 3rd Embodiment are one oil pump which consists of three or more gears. Specifically, as shown in FIGS. 7 to 9, the first set rotor A is configured by a first gear 141, a second gear 142, a discharge port 144, and a suction port 145 in the casing 140. . Further, the second rotor B is configured by a second gear 142, a third gear 143, a discharge port 146 and a suction port 147 in the casing 140. That is, one oil pump including the first set rotor A and the second set rotor B by three gears is configured. The configurations of the discharge passages, the return passages, and the pressure control valves C as pressure control devices in the first and second rotors A and B of the third embodiment are the same as those in the first embodiment.

  The operation of the pressure control valve C in the first group rotor A and the second group rotor B of the third embodiment will be described. First, when the first group rotor A and the second group rotor B are in the low rotation range, that is, when the engine speed is in the low rotation range, the state of FIG. The operations of the valve unit 51 and the second valve unit 52 are the same as those in FIG. Under this situation, the rotation speed and discharge pressure characteristic table [see FIG. 5A] or the rotation speed and discharge flow rate characteristic table [see FIG. 5B] are low rotation regions.

  Furthermore, let the state which the rotation speed of the engine rose be a middle rotation area. This state is the state of FIG. 8, and the operation of the pressure control valve C is the same as that of FIG. This middle rotation region appears in the pressure characteristic table (see FIG. 5) of the rotational speed and the discharge pressure or the discharge flow rate. Thus, the total pressure connecting line of the first set rotor A and the second set rotor B can be made substantially the same as the pressure characteristic of the conventional oil pump.

  Furthermore, the state in which the engine speed has increased is defined as a high engine speed range. In this state, the state is as shown in FIG. 9, and the operation of the pressure control valve C is the same as that in FIG. This high rotation range appears in the pressure characteristic table (see FIG. 5) of the rotational speed and the discharge pressure or the discharge flow rate, and the first set rotor A rises slowly, but the second set rotor B is in the closed state. Yes, the total pressure connection line of the first set rotor A and the second set rotor B is only the first set rotor A. Thus, since the pressure of the 2nd group rotor B falls, since friction (torque) reduces, efficiency rises.

It is a system diagram of a 1st embodiment of the present invention, and is a state figure in a low engine speed range. It is a system diagram of a 1st embodiment of the present invention, and is a state figure in an engine middle speed range. It is a system diagram of a 1st embodiment of the present invention, and is a state figure in a high engine speed range. 1 is a simplified system diagram of the present invention. (A) is a characteristic table of engine speed and discharge pressure in the present invention, and (B) is a characteristic table of engine speed and discharge flow rate in the present invention. It is a system diagram of a second embodiment of the present invention, and is a state diagram in a low rotation range of the engine. It is a system diagram of a third embodiment of the present invention, and is a state diagram in a low engine speed range. It is a system diagram of a third embodiment of the present invention, and is a state diagram in an intermediate rotation region of an engine. It is a system diagram of a third embodiment of the present invention, and is a state diagram in a high engine speed range.

Explanation of symbols

First set rotor A, engine E, first discharge path 1, first return path 2, second set rotor B,
The second discharge path 3, the second return path 4, the valve body 5, the first valve section 51, the second valve section 52, the discharge port 30,
Small diameter connecting portion 53, pressure control valve C.

Claims (3)

A first discharge passage for oil supply from the first rotor assembly to an engine, a first feedback path for feeding back to the suction passage of the first rotor assembly, a second discharge for oil feeding to the engine from the second rotor assembly A valve body comprising a passage, a second return passage returning to the suction passage of the second set rotor, a first valve portion, a small diameter connecting portion, and a second valve portion is discharged from the second set rotor. consists of a pressure control valve disposed between the outlet first discharge passage, wherein the first discharge passage and the second discharge passage is connected to the low rotational speed range, the first discharge passage and the through Rutotomoni with only the second discharge passage is opened, the medium engine speed range, the first discharge passage and the and the second discharge passage communicating with the opening, the first feedback path is closed the second in a state in which the feedback path is opened, and the high speed range, the second discharge passage is the first discharge passage is closed the opening communicating with Rukoto It is eliminated, in the state in which the first feedback path and said second feedback path which is opened, a pressure control device in an oil pump, characterized in that formed by each controlled channel.   2. The pressure control apparatus for an oil pump according to claim 1, wherein each of the first set rotor and the second set rotor is configured as a separate oil pump.   2. The pressure control device for an oil pump according to claim 1, wherein the first set rotor and the second set rotor are configured as one oil pump having three or more rotors.

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