JP4029382B2 - LPG pressure regulator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pressure regulator used in a system for supplying LPG (liquefied petroleum gas) to an engine by adjusting the vaporized gas to a predetermined positive pressure and injecting the gas into an intake pipe, and in particular, the LPG is required at low temperatures. The present invention relates to a pressure regulator having a function capable of being a vaporized gas.
[0002]
[Prior art]
The use of LPG as a fuel for spark ignition engines is widely known, and vaporized gas decompressed to about atmospheric pressure using a vaporizer (regulator) and a mixer is sucked into an intake pipe and supplied to the engine. Instead of the conventionally known method, a method for injecting the liquid into the intake pipe as described in Japanese Utility Model Laid-Open No. 59-43659, and Japanese Patent Laid-Open No. 6-17709, etc. Has been proposed to adjust the vaporized gas to a predetermined positive pressure and inject it into the intake pipe.
[0003]
However, the method of injecting the liquid as it is into the intake pipe uses the saturated vapor pressure in the cylinder as it is or injects it by further pressurizing with a pump. However, the liquid LPG is easily affected by temperature. Since it has an unstable property of being vaporized, a method of adjusting and injecting it to vapor gas having a predetermined positive pressure has become the mainstream at present.
[0004]
The pressure regulator that converts the high-pressure liquid LPG in the cylinder into a predetermined positive pressure vaporized gas within a pressure range in which the gas state is stably maintained, heats the liquid LPG sent from the cylinder, In a system for supplying the engine by injecting the vaporized gas into the intake pipe and supplying the heat exchange unit and the pressure regulating unit that depressurizes the vaporized gas to a predetermined positive pressure and sends it to the target device. A combination of a PTC heater and engine cooling water for heating the liquid LPG in the heat exchange section has been proposed. That is, the liquid LPG is heated and vaporized by a PTC heater at a low temperature before the engine warms up, and is heated and vaporized by the engine cooling water after the engine is warmed up, so that electric resistance heat is used for a short time when the engine cooling water temperature is low. In this way, vaporized gas is obtained.
[0005]
FIG. 8 shows a pressure regulator that uses a PTC heater and engine cooling water that are currently provided. A heat exchange unit 51 that uses liquid LPG as a vaporized gas includes a heat exchange chamber 52, a PTC heater 53, and hot water. The pressure regulating unit 61 that has the chamber 54 and makes the vaporized gas a predetermined positive pressure has a pressure regulating chamber 62, a diaphragm 63, and an inlet valve 66.
[0006]
The PTC heater 53 is fitted into a recess 57 formed on the outer wall of the heat exchanging portion 51, and pushes the free end of a leaf spring-like electrode 59 that covers the recess 57 and is fixed to a cover plate 58 attached to the outer wall. By being applied, the heat exchange chamber 52 is superposed on one wall 55 without any gap. The hot water chamber 54 is formed along a wall 56 facing the wall 55 on which the PTC heaters 53 are stacked. The liquid LPG fed from the cylinder through the inlet 52a into the heat exchange chamber 52 is heated and vaporized by the heat generated by the PTC heater 53 using the wall 55 as a heat exchange surface, or the other wall 56 as a heat exchange surface. The hot water chamber 54 is heated and vaporized by the heat of the engine cooling water flowing from the inlet 54a to the outlet 54b.
[0007]
The volume of the pressure adjusting chamber 62 is variable by a diaphragm 63 on which an adjustment spring 64 is applied. An inlet valve 66 is attached to a lever 65 that rotates according to the displacement of the diaphragm 63 and communicates with an outlet 52 b of the heat exchange chamber 52. The valve seat port 67 to be opened and closed is opened. When the vaporized gas in the pressure regulating chamber 62 is sent from the outlet 62a to the target injection valve, the pressure in the pressure regulating chamber 62 becomes lower than the set pressure, and the inlet valve 66 opens the valve seat 67 to perform heat exchange. When the vaporized gas in the chamber 52 flows into the pressure regulating chamber 62 and becomes higher than the set pressure, the inlet valve 66 closes the valve seat 67. As a result, the pressure adjusting chamber 62 holds vaporized gas adjusted to a predetermined positive pressure, generally about 30 KPa. Even if the liquid LPG is not completely vaporized in the heat exchange chamber 52 and the liquid LPG is mixed in the vaporized gas flowing into the pressure adjusting chamber 62, the liquid LPG is vaporized by reducing the pressure during the inflow. 62 holds only vaporized gas.
[0008]
[Problems to be solved by the invention]
Since one surface of the PTC heater 53 in the pressure regulator faces the atmosphere with the cover body 58 sandwiched therebetween, most of the heat generated from this surface is released into the atmosphere and from the surface superimposed on the wall 55. Only the heat generated is used for heating the liquid LPG, and it takes a long time to reach a temperature at which a sufficient heat exchange function can be achieved from the start of energization, and the purpose is to obtain vaporized gas in a short time at low temperatures. Not only is it unsatisfactory to achieve, but it has a problem that it is difficult to stably obtain a vaporized gas that is not mixed with liquid LPG with a limited size and number of PTC heaters because of poor thermal efficiency. .
[0009]
In addition, for a vaporizer (regulator) that uses liquid LPG as a vaporized gas at atmospheric pressure, the primary chamber into which liquid LPG is fed is heated by a PTC heater, for example, Japanese Patent Laid-Open Nos. 8-303304 and 11-324813. However, the PTC heater also has the same problem as described above because one surface is superimposed on the wall of the primary chamber and the other surface faces the atmosphere.
[0010]
The present invention has a pressure regulator in which liquid LPG is heated by a PTC heater at a low temperature to generate vaporized gas. Since the amount of heat released from the PTC heater to the atmosphere is large, it takes a long time to generate vaporized gas. In order to solve the above-mentioned problem that the thermal efficiency is not good, the liquid LPG can be generated in a short time and the vaporized gas can be stably generated with high thermal efficiency. It is intended to have a heat exchanging part that can.
[0011]
[Means for Solving the Problems]
A heat exchange chamber having a heat exchange chamber, a PTC heater, and a hot water chamber through which engine coolant passes, heats the liquid LPG fed into the heat exchange chamber into vaporized gas, and vaporization made by the heat exchange portion In order to solve the above-mentioned problem that the pressure regulator of the LPG having a pressure regulator that adjusts the gas to a predetermined positive pressure and sends it to an injection valve installed in the engine intake pipe, at least one PTC heater is an electrode. The heat exchange chamber has a storage chamber that is open on the outer wall and protrudes to the inside, with the surfaces facing away from each other being exposed on both sides and held by the holding body. The holding body is fitted in the storage chamber, and the surfaces of the PTC heaters facing opposite to each other are overlapped with the opposing wall portions of the storage chamber, respectively, and the liquid LPG fed into the heat exchange chamber is placed in the PTC heater. Flow along the wall He was a shall.
[0012]
The surface of the PTC heater that is not superimposed on the wall portion of the housing chamber, which is the heat exchange surface, faces each other inside the holding body with the electrode in between, and these surfaces do not face the atmosphere outside the heat exchange unit Therefore, the amount of heat released to the atmosphere is extremely small, and in order to heat the entire wall surrounding the collection chamber, it is possible to reach the temperature at which the liquid LPG is turned into a vaporized gas in a short time from the start of energization. In addition, since the amount of heat released to the outside atmosphere is small and the liquid LPG flows along the two wall portions overlaid with the PTC heater, the vaporized gas can be stably obtained even at a large flow rate with high thermal efficiency. it can.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
The embodiment of the present invention will be described with reference to the drawings. In the first embodiment shown in FIGS. 1 to 4, the heat exchanging unit 1 has an inlet 3 and a generation of a liquid LPG sent from a cylinder (not shown). The heat exchange chamber 2 that has the outlet 4 for sending the vaporized gas to the pressure regulating chamber 26 to one side and is almost facing each other, and the partition wall 6 between the heat exchange chamber 2 and the pressure regulating chamber 26 are provided. It has a hot water chamber 7 through which engine cooling water passes from the inlet 8 to the outlet 9 and four disc-shaped PTC heaters 10 arranged inside the heat exchange chamber 2.
[0014]
Two of the PTC heaters 10 are held by one holding body 11. That is, the holding body 11 includes two recesses 13 which are separated from each other by the mounting wall 12 and open to the opposite side surface, and an annular stepped portion 14 formed along the outer peripheral edge of the open end of these recesses 13. The leaf spring-like electrode 15 overlapped at the center of both surfaces of the mounting wall 12 is fixed to the mounting wall 12 by a rivet 17 penetrating the mounting wall 12 together with the terminal 16 stacked on one side thereof, and the inside of the recess 13 The PTC heater 10 is fitted in the stepped portion 14, and the electrode 15 is in contact with the surface facing the recess 13. The electrode 15 applies a force in a direction to push the surfaces exposed on both side surfaces of the holding body 11 from the step portion 14 to the PTC heater 10 by its spring action. The terminal 16 protrudes outside the holding body 11 and is connected to a power source (not shown). The PTC heater 10, the holding body 11, the electrode 15, and the terminal 16 constitute a PTC unit 18.
[0015]
The heat exchange chamber 2 has an accommodation chamber 20 open to the outer wall 19 where the inlet 3 is provided, with a space around and protruding inside. Two PTC units 18 are fitted into the housing chamber 20 adjacent to each other, and are prevented from coming out of the housing chamber 20 by a pressing plate 22 that closes the open surface and is fixed to the outer wall 19. In addition, the surfaces of the PTC heaters 10 facing in opposite directions with the electrode 15 interposed therebetween are pressed against the wall portions 21a and 21b of the wall 21 forming the housing chamber 20 facing each other by the spring action of the electrode 15. It is piled up with.
[0016]
On the other hand, the heat exchange chamber 2 has a flat partition member 5 that shields between the inlet 3 and the outlet 4 and extends to the vicinity of the opposite end thereof, and the liquid LPG fed from the inlet 3 is Each of the wall portions 21a, 21b flows along the half area toward the opposite end, and then flows along the other half area toward the outlet 4.
[0017]
According to the present embodiment, the surface of the PTC heater 10 that is not overlapped with the wall portions 21a and 21b is opposed to the inside of the holding body 11 with the electrode 15, the recess 13 and the mounting wall 12 interposed therebetween, and this is the PTC unit. 18 is inserted into the heat exchange chamber 2, the amount of heat released to the atmosphere outside the heat exchange section 1 is extremely small, and the entire wall 21 of the storage chamber 20 is heated. In combination with the direct heating of the wall portions 21a and 21b on which the PTC heater 10 is superimposed, the temperature reaches the temperature at which the liquid LPG is turned into a vaporized gas in a short time from the start of energization.
[0018]
Further, the liquid LPG that has entered the heat exchange chamber 2 from the inlet 3 is divided into two flows along the opposite wall portions 21a and 21b on which the PTC heaters 10 are stacked, and is in contact with almost the entire surface of the wall 21 to exchange heat. To reach the outlet 4, so that heat exchange is performed with high thermal efficiency combined with a small amount of heat released to the outside atmosphere, and vaporized gas can be obtained stably even at extremely low temperatures or at large flow rates. Can do.
[0019]
Furthermore, according to the present embodiment, the PTC unit 18 having a sandwich structure in which the two PTC heaters 10 and their electrodes 15 are assembled to the holding body 11 is fitted into the storage chamber 20 so that it can be taken in and out. There is an advantage that not only the installation of the PTC heater 10 to the heat exchanging unit 1 is very easy, but also the maintenance, repair, replacement and the like can be easily performed.
[0020]
Next, the pressure adjusting unit 23 is attached to a pressure adjusting chamber 26 whose volume is variable by a diaphragm 25 to which an adjusting spring 24 is applied, and a lever 27 that rotates according to the displacement of the diaphragm 25 and communicates with the outlet 4. An inlet valve 28 for opening and closing the valve seat 29 is provided. When the vaporized gas in the pressure regulating chamber 26 is sent from the delivery port 26a to the injection valve, the pressure in the pressure regulating chamber 26 becomes lower than the set pressure. 28 opens the valve seat 29 and allows the vaporized gas in the heat exchange chamber 2 to flow into the pressure regulating chamber 25. When the pressure becomes higher than the set pressure, the inlet valve 28 closes the valve seat 29 and generally enters the pressure regulating chamber 26. Is the same as the conventional one in that the vaporized gas decompressed to a constant positive pressure of about 30 KPa is retained.
[0021]
FIGS. 5 to 7 show a second embodiment of the heat exchanging unit 1. The heat exchanging unit 1 shows the inlet 3 of the liquid LPG and the generated vaporized gas sent from a cylinder (not shown). An engine provided along a partition 6 between the heat exchange chamber 2 and the pressure regulating chamber; A hot water chamber (not shown) that allows the cooling water to pass therethrough and four disk-shaped PTC heaters 10 arranged inside the heat exchange chamber 2 are the same as those in the first embodiment.
[0022]
In the present embodiment, four PTC heaters 10 are held by one holding body 31. That is, the holding body 31 has two sets of two indentations 33 that are partitioned from each other by the mounting wall 32 and open to the opposite side, and are close to each other along the outer peripheral edge of the open end of these indentations 33. The annular spring-shaped step portion 34 is provided, and the leaf spring-like electrode 15 overlapped at the center of both surfaces of the two mounting walls 32 is penetrated through the mounting wall 32 together with the terminal 16 stacked on one side thereof. The rivet 17 is fixed to the mounting wall 32 and installed inside the recess 33, and the PTC heater 10 is fitted into the step portion 34, and the electrode 15 is in contact with the surface facing the recess 33. The electrode 15 applies a force in the direction of pushing out from the step portion 34 to the PTC heater 10 by its spring action, and the terminals 16 protrude parallel to the outside of the holding body 31 and are connected to the power supply side (not shown). The PTC heater 10, the holding body 31, the electrode 15, and the terminal 16 constitute a PTC unit 38.
[0023]
The heat exchange chamber 2 includes an outer wall portion provided with the inlet 3 and an outer wall portion opposite to the inlet 3 and the outlet 4, the collection chamber 40 opened on the outer wall 39 on the side where the inlet 3 and the outlet 4 are provided, A continuous space is provided along the partition wall 6 so as to protrude inside. The PTC unit 38 is fitted into the housing chamber 40 without any gap, and is prevented from coming out of the housing chamber 40 by a press plate 42 that closes the open surface and is fixed to the outer wall 39. Further, the surfaces of the PTC heaters 10 facing in opposite directions with the electrode 15 interposed therebetween are pressed against the mutually facing wall portions 41a and 41b of the wall 41 forming the housing chamber 40 by the spring action of the electrode 15. It is piled up with.
[0024]
Also in the present embodiment, the surface of the PTC heater 10 that is not overlapped with the wall portions 41a and 41b is opposed to the inside of the holding body 31 with the electrode 15, the recess 33, and the mounting wall 32 interposed therebetween, and this is the PTC unit. 38 is inserted into the heat exchange chamber 2, the amount of heat released to the atmosphere outside the heat exchange section 1 is extremely small, and the entire wall of the collection chamber 40 is heated, particularly a PTC heater. Combined with the direct heating of the wall portion on which 10 is stacked, the temperature at which liquid LPG is vaporized gas can be reached in a short time from the start of energization.
[0025]
The liquid LPG that has entered the heat exchange chamber 2 from the inlet 3 flows between the outer wall portion provided with the inlet 3 and the one wall portion 41a on which the PTC heater 10 is overlapped, and then the partition wall 6 and the PTC heater 10. Flows between the other wall portion 41b on which the gas is piled up to reach the outlet 4, during which the entire surface of the wall 41 is contacted and the amount of heat released to the outside atmosphere is small, thereby exchanging heat with high thermal efficiency. The vaporized gas can be stably obtained even at extremely low temperatures or at a large flow rate.
[0026]
In addition, according to the present embodiment, the single PTC unit 38 in which the four PTC heaters 10 and their electrodes 15 are assembled into one holding body 31 to form two sandwich structures is provided in the storage chamber 40. Therefore, the installation of the PTC heater in the heat exchanging unit 1 is further simplified and facilitated, and the maintenance, repair, replacement and the like can be performed very easily.
[0027]
Needless to say, the number of PTC heaters 10 is not limited to four, and may be two or six depending on the specifications and capacity of the pressure regulator. The PTC heater 10 is energized by detecting the temperature of the engine cooling water. When the temperature is low before the engine is warmed up, the PTC heater 10 is energized to vaporize the liquid LPG and the engine is cooled after the engine is warmed up. When the water temperature becomes sufficiently high, energization is stopped and the engine cooling water is circulated through the hot water chamber 7 to heat and vaporize the liquid LPG.
[0028]
Here, the conventional product shown in FIG. 8 and the product of the present invention according to the embodiment shown in FIGS. 1 to 4 are used, and the same number of PTC heaters having the same capacity are installed in the same heat exchange chamber. FIG. 9 shows the test results comparing the heat exchange performance with flowing water at a flow rate. (A) is the heat efficiency calculated as specific heat = 1 Kcal / kg · ° C, 1 Kcal = 1.163 W, (B) is the power consumption W of the PTC heater (voltage is constant 12 V), (C) is the inlet and outlet of the heat exchange chamber The temperature difference ΔT ° C. of water at each time change, the product of the present invention represented by a solid line and the conventional product represented by a broken line are slightly disadvantageous in terms of power consumption, but the thermal efficiency It can be seen that the product of the present invention is greatly superior in terms of temperature difference. From this test result, it is understood that according to the present invention, the liquefied gas can be vaporized well with high thermal efficiency.
[0029]
【The invention's effect】
As described above, according to the present invention, the pressure regulator including the heat exchange unit that heats the liquid LPG with the PTC heater instead of the engine cooling water at the low temperature to generate the vaporized gas is transferred to the heat generated by the PTC heater. The LPG can be turned into vaporized gas in a short time from the start of energization, and the engine can be started quickly at low temperatures, and heat exchange is performed with high thermal efficiency to vaporize even at extremely low temperatures and large flow rates. Gas can be obtained stably.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing a first embodiment of the present invention.
2 is a cross-sectional view taken along line AA in FIG.
FIG. 3 is an enlarged cross-sectional view taken along the line BB in FIG.
FIG. 4 is a partially cut front view of the PTC unit according to the first embodiment.
FIG. 5 is a partial longitudinal sectional view showing a second embodiment of the present invention.
6 is a cross-sectional view taken along line AA in FIG.
7 is an enlarged cross-sectional view taken along line BB in FIG.
FIG. 8 is a longitudinal sectional view showing a conventional example.
FIG. 9 is a diagram showing test results for comparing heat exchange performance between the product of the present invention and a conventional product.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Heat exchange part, 2 Heat exchange room, 7 Hot water room, 10 PTC heater, 11, 31 holder, 15 electrodes, 18, 38 PTC unit, 20, 40 Storage room, 21a, 21b, 41a, 41b Wall part,

Claims (5)

A heat exchange section having a heat exchange chamber, a PTC heater, and a hot water chamber through which engine cooling water passes, and a heat exchange section that heats the liquid LPG fed into the heat exchange chamber into vaporized gas, and the heat exchange section. In an LPG pressure regulator comprising an adjusting unit that adjusts the vaporized gas to a predetermined positive pressure and sends it to an injection valve installed in the engine intake pipe,
Each of the PTC heaters is held by a holding body with at least one of the electrodes facing in opposite directions with electrodes sandwiched on both sides, and the heat exchange chamber has an interior chamber opened to the outside wall. Projecting into
The holding body is fitted into the storage chamber, and the surfaces of the PTC heaters facing in opposite directions are overlapped with the facing wall portions of the storage chamber, respectively, and sent to the heat exchange chamber. The liquid LPG flows along the wall portion on which the PTC heaters are stacked.
LPG pressure regulator characterized by the above. 2. The LPG pressure regulator according to claim 1, wherein the holding body holds two PTC heaters to constitute a PTC unit, and at least one of the PTC units is fitted in the housing chamber. 3. 2. The LPG pressure adjustment according to claim 1, wherein the holding body holds a required number of PTC heaters to form a single PTC unit, and the single PTC unit is fitted in the housing chamber. 3. vessel. The heat exchange chamber has a liquid LPG inlet and a vaporized gas outlet side by side and a partition member that bisects the two wall portions on which the PTC heaters are stacked. The liquid LPG fed from the inlet is divided into two parts and flows along one region of the wall portion defined by the partition member, and then toward the outlet along the other region. The LPG pressure regulator according to claim 1, wherein the pressure regulator is flowable. The heat exchange chamber has an inlet for liquid LPG and an outlet for vaporized gas shifted to one side, and the two wall portions on which the PTC heaters are stacked are liquid LPG fed from the inlet. 2. The LPG according to claim 1, wherein the collection chamber protrudes into the heat exchange chamber so that the first chamber flows along one wall portion and then flows toward the outlet along the other wall portion. Pressure regulator.

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