JPH0745805B2 - Removable engine oil heating unit and engine lubrication device equipped with the unit - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an engine oil heating device and an engine lubrication system including the device for improving startability of a cold start engine, and more particularly to a removable engine. Regarding the oil heating unit.

[Related technology]

In the case of gasoline engines as well as diesel engines, the engine startability in cold weather depends on the compression pressure and thus on the cranking speed. The higher the cranking speed, the easier the engine will start and the lesser the load on the battery. At cold start under cold conditions, the viscosity of the engine oil increases, so the driving force of the oil pump becomes a value that cannot be ignored. For example, during cold start when the outside air temperature is -25 ° C, about 10% of the output of the starter is consumed to drive the oil pump, so that the cranking speed is limited and the startability deteriorates.

Therefore, the applicant has previously proposed to provide an oil heating device upstream of the oil pump to heat the engine oil during cold start to reduce its viscosity and reduce the drive torque of the oil pump ( (See Japanese Patent Application No. 61-250677 and Japanese Patent Application Laid-Open No. 62-111110) dated November 11, 1985). According to this, since the torque required to drive the oil pump is reduced to about 1/10, the load on the starter is reduced, the cranking speed is increased, and the engine can be started in a shorter time.

[Problems to be Solved by the Present Invention]

In the oil heating device, a PTC (positive temperature characteristic) heater element is used as a heating element, and this heater element is arranged in an oil pipe from an oil sump to an oil pump. Therefore, it has been difficult to mount on the engine, maintain and inspect, and mass production has been difficult.

[Object of the Invention]

An object of the present invention is to provide an engine oil heating device that can be mass-produced, can be easily attached to and detached from an engine, can be easily maintained and inspected, and can be easily and inexpensively replaced with components. is there.

Another object of the present invention is to provide an engine lubrication device including the engine oil heating device.

[Summary of means and actions for solving problems]

The present invention provides, as means for solving the above-mentioned problems, a detachable engine oil heating unit described in the claims and an engine lubrication apparatus including the unit.

In the engine oil heating unit or the engine lubricating device of the present invention, the oil that lubricates the engine is sucked from the oil sump into the oil pump through the oil suction passage. In the opening formed in a part of the wall surface,
A metal main body of a hollow cylindrical engine oil heating unit is detachably mounted by a screwing structure, and its base end is closed by an insulating material and its front end is open. Further, the intermediate portion is provided with a radial through hole that communicates the inside and outside thereof, and a portion closer to the tip than the through hole is inserted in the oil suction passage so that a gap remains in the periphery. A hollow cylindrical PTC electric heater element is detachably inserted and held inside a portion of the metal main body located in the oil suction passage near the tip.

The engine oil sucked into the oil pump from the oil sump through the oil suction passage when the engine is in operation flows partially from the opening at the tip of the heating unit into the hollow cylindrical electric heater element and then through the through hole. In addition to flowing out, the other part flows from the opening at the tip through the gap between the oil suction passage and the outer circumference of the electric heater element. Moreover, since there is no other flow, the engine oil supplied to the oil pump must be inside the electrothermal heater element.
Alternatively, it flows through an external gap and is sent to the oil pump.

Therefore, when it is necessary to heat the engine oil,
When power is supplied to the PTC electric heater element from the outside of the base end of the metal body, the engine oil is heated not only in the internal space of the electric heater element but also in the external gap, so the heat transfer surface doubles and the efficiency is improved. It will be heated well.
As a result, while maintaining the same amount of heat generation, the electrothermal heater element,
Therefore, the entire engine lubrication device including the heating unit itself and the oil suction passage can be downsized. Moreover, since the heating unit heats only the oil flowing through the oil suction passage and does not heat a large amount of oil in the oil sump, it is possible to quickly raise the required amount of oil to a predetermined temperature with a small amount of electric power. You can
Furthermore, since the heating unit is detachable due to the screwing structure, maintenance and inspection are easy.

〔Example〕

Referring to FIG. 1, an oil pan 12 forming an oil sump forming means is provided under a cylinder block 10 of an engine.
Are mounted by bolts 14, and an oil sump 16 is formed by the oil contained in the oil pan 12.
After the oil in the oil sump 15 is filtered by the oil strainer 18, the oil is sucked into the oil pump 22 through the oil suction passage 20 and is pressure-fed to the oil gallery 24. In the illustrated embodiment, the oil pan 12 is integrally joined with a semi-cylindrical partition plate 26 by welding or the like.
An enlarged portion 28 of the oil suction passage 20 is formed by 26 and. The left end of this enlarged part is the vertical end wall 30 of the oil pan 12.
Limited by. An outlet pipe 32 is formed integrally with the partition plate 26, and is connected to the passage 20 in the cylinder block 10 via an O-ring 34.

The vertical end wall 30 of the oil pan 12 is provided with a circular opening 36 substantially aligned with the enlarged portion 28, and a cylindrical mounting socket 38 is integrally provided along the opening 36. The oil heating unit 40 is inserted into the enlarged portion 28 of the oil suction passage 20 through the opening 36 at a half portion near the tip thereof, so that a clearance for the oil to flow remains around the mounting socket.
It is attached to 38.

Referring to FIG. 1 and FIG. 2, an oil heating unit
Reference numeral 40 has a substantially cylindrical main body 42 made of metal, and the main body 42 is provided with a mounting structure 44 for detachably mounting the heating unit 40 in the mounting socket 38. In the illustrated embodiment, the mounting structure 44 comprises an outer threaded portion 46 provided on the outer circumference of the body 42 over a predetermined axial length, and an inner thread that engages with this is formed on the inner circumference of the mounting socket 38. . A hexagonal head portion 48 is formed on the main body 42, and the heating unit 40 can be easily attached / detached to / from the mounting socket by rotating it with a tool such as a wrench. An O-ring 50 provides a seal between the socket 38 and the body 42.

A cylindrical PTC electric heater element 52 is detachably fitted to the right end of the main body 42. Instead of the cylindrical shape, the heater element 52 may have a honeycomb structure or a polygonal columnar structure. As can be seen from FIG. 2, a plurality of axial slots 54 are provided at the right end of the main body 42, and most of the outer peripheral surface of the heater element 52 makes heat transfer contact with the oil in the enlarged portion 28 to transfer the oil. It is designed to heat effectively. By cutting off the slot 54, a plurality of holding claws 56 are formed at the right end of the main body 42.
The heater element 52 is held through the insulating ring 58 by bending the end portion of the heater element inward.

The PTC electrothermal heater element 52 is a conductive ceramic having a positive temperature characteristic, and its electrical resistance changes rapidly around a specific temperature. The outer electrode and the inner electrode (not shown) are deposited on the outer peripheral surface and the outer peripheral surface of the PTC heater element 52 over substantially the entire surface by a sintering method or the like. An electric current flows through the device to generate heat. The outer electrode is a metal body 42
Is in electrical contact with.

Electric power is supplied to the inner electrode via the power supply means 60. The power supply means 60 comprises a center electrode 64 positioned coaxially with the body 42 by means of an insulating resin 62. The center electrode 64 has a cylindrical portion 66 that is spaced radially inward from the main body 42, and a rod 70 that is connected to a lead wire 68. By press-fitting the PTC element 52 between the main body 42 and the cylindrical portion 66, the inner electrode of the PTC element 52 and the central electrode cylindrical portion 66 are electrically connected. PTC element 5 of the cylindrical portion 66
A plurality of T-shaped notches (the T-shaped head extends in the circumferential direction, and the legs extend axially to the right end of the cylindrical portion 66 in the portion engaging with 2. In FIG. Only the head of the letter is shown). With these T-shaped notches, the cylindrical portion 66
The spring characteristic is given to the right end of the PTC element 5
Elastically abut the inner electrode of 2.

In order to allow the oil inside the PTC element 52 to flow toward the outlet pipe 32, the main body 42 is provided with a plurality of through holes 72, and the center electrode 64 is also provided with similar through holes. is there.

An insulating boot 74 is attached to the left end of the main body 42, and the lead wire 68 extends through the boot 74 and is connected to the control circuit 76. A thermistor type temperature sensor 78 is attached to the oil pan 12, and its output is sent to the control circuit. In addition, the engine has a known engine speed sensor 80.
Is provided, and its output is also sent to the control circuit 76. As the control circuit 76, the one disclosed in the above-mentioned JP-A-62-111110 can be used. Alternatively, the control circuit 76, when the key switch 82 is ON, the oil temperature detected by the temperature sensor 78 is equal to or lower than the set value, and the engine speed detected by the speed sensor 80 is the cranking speed. It can be configured to energize the PTC heater element 52 when in range.

Next, to explain the operation of the oil heating unit 40,
When the key switch 85 is turned on, the PTC heater element 5
Power is supplied to 2, and the element 52 generates heat. Since the PTC element 52 has a positive temperature characteristic, a large current flows and the temperature instantly rises at a low temperature. When the temperature reaches a constant temperature, the electric resistance thereof rapidly increases and the current is reduced, so that the temperature of the element 52 is maintained constant. Next, when a starter switch (not shown) is turned on to start cranking, the oil pump 22 rotates, and the oil in the oil sump 16 is sucked into the oil pump through the oil suction passage 20 and its enlarged portion 28. Be done. Enlarged section 28
Inside, the oil flows both on the outside and on the inside of the heater element 52, so that the oil contacts both the outer peripheral surface and the inner peripheral surface of the element 52 and the oil is effectively heated. Since the oil whose viscosity has been lowered by heating is sucked into the oil pump 22, the driving force of the oil pump becomes extremely small and the load on the starter is reduced. Therefore, the engine is cranked at a high cranking speed and easily starts in a short time. After the start, the power supply to the heater element 52 is stopped.

FIG. 3 shows a second embodiment of the engine lubrication device. In this embodiment, an oil pump case 104 containing an oil pump 102 is attached to the front part of the cylinder block 100. The oil pump case 104 has an extension 106 that extends downwardly, and the oil heating unit 108 is fixed to the extension 106 by being screwed in from the outside. Oil heating unit
108 is the same as the unit 40 shown in FIGS. 1 and 2. In this embodiment, the oil sump forming means is constituted by the case extension portion 106 and the oil pan 110, the front portion of the oil pan 110 is liquid-tightly joined to the extension portion 106, and the remaining portion is directly joined to the cylinder block 100. Has been done. Further, in this embodiment, a strainer pipe 114 having an enlarged portion 112 is bolted to the case extension portion 106, and the PTC heater element of the oil heating unit 108 has the enlarged portion 112.
It is extended within. Exit pipe in the embodiment of FIG.
Compared with the case where 32 is connected to the oil passage 20 through the O-ring 34, the strainer pipe 114 is fixed to the case extension portion 106 in the embodiment of FIG. 3, so that the strainer pipe 114 can be easily positioned. it can.

This lubricating device is equipped with a relief valve 118 for adjusting the hydraulic pressure in the oil gallery 116 to a constant pressure. In the preferred embodiment of the invention, the relief port 120 of the relief valve 118 is connected to the inlet of the enlarged section 112 by a return pipe 122. The advantages of this configuration are as follows. In other words, when cranking for cold start, the flow resistance of the moving part of the engine is large, so the oil heating unit
Most of the oil heated by 108 tends to be returned from the relief valve 118 to the oil sump. In this embodiment, since the heated oil is sent to the inlet of the expansion section 112, the power consumption of the PTC heater element can be saved.

〔The invention's effect〕

The oil heating unit of the present invention is not only downsized because the heat transfer surface of the PTC electric heating element can be doubled, but also the required amount of engine oil can be quickly raised to a predetermined temperature with low power consumption. Can be warmed. Moreover, since it is composed of components having an extremely simple structure (a cylindrical main body, a cylindrical PTC element, etc.), it can be mass-produced extremely easily and inexpensively.

Further, since the oil heating unit is configured to be externally attached to the oil sump forming means by using a simple tool such as a wrench, it can be attached to the engine extremely easily and quickly with a few steps. Improve engine productivity. Furthermore, maintenance and inspection of the oil heating unit becomes extremely easy, and the entire unit can be easily replaced with a new one as needed. Since the PTC heater element is detachably held in the main body, it is possible to replace only the heater element, in which case the economical burden on the user is further reduced. Moreover, since the PTC heater element is formed in a cylindrical shape, it has excellent vibration resistance and is not easily damaged.

If the body of the unit is provided with a plurality of axial slots, the contact area between the element and the oil increases, so that the oil can be quickly heated with the minimum power consumption.

When using a cylindrical center electrode, mechanical mooring and electrical connection can be made simultaneously by simply press fitting the PTC heater element between the body and the center electrode, and the unit can be assembled or the element replaced. Easy to do.

When the central electrode is provided with the T-shaped notch, the inner electrode of the heater element and the central electrode are elastically engaged with each other, so that the electrical connection between them is ensured.

The engine lubrication device of the present invention provides a detachable mounting structure for the oil heating unit, and the heat generating portion of the unit can be easily positioned within the enlarged portion of the oil passage.

When the relief port of the relief valve is connected to the inlet of the expansion portion, the preheated oil is returned to the expansion portion, so that the power consumption of the heater can be saved.

[Brief description of drawings]

FIG. 1 is a sectional view showing the oil heating unit of the present invention mounted on an oil pan, FIG. 2 is a perspective view of the oil heating unit, and FIG. 3 is a second embodiment of the engine lubricating device of the present invention. Show. 12 …… Oil sump forming means (oil pan), 16 …… Oil sump, 20 …… Oil suction passage, 22 …… Oil pump, 24 …… Oil gallery, 26 …… Partition plate, 28 …… Oil suction passage Enlarged part, 30 …… Vertical end wall of oil sump forming means, 36 …… Vertical wall opening, 38 …… Mounting socket, 40 …… Oil heating unit, 42 …… Unit body, 44 …… Mounting structure, 46 …… Outer screw part, 48 …… Hexagonal head, 52 …… PTC electric heater element, 54 …… Axial slot, 56 …… Holding claw, 60 …… Power supply means, 64 …… Center electrode, 66 ...... Cylindrical part of the center electrode, 68 ...... Lead wire, 72 …… Main body through hole, 102 …… Oil pump, 104 …… Oil pump case, 106 …… Case extension, 108 …… Oil heating unit, 106,110 …… Oil sump forming means, 110 …… Oil pan, 112 …… Oil suction passage Enlarged part, 118 …… Relief valve, 122 …… Return pipe.

Front page continued (72) Inventor Masao Wakayama 14 Iwatani, Shimohakaku-cho, Nishio-shi, Aichi Japan Auto Parts Research Institute (72) Inventor Ryo Sato 1 Toyota-cho, Toyota-shi, Aichi Toyota Motor Co., Ltd. (56) References JP 54-144526 (JP, A) JP 59-183016 (JP, A)

Claims (12)

[Claims] 1. An opening formed in a part of a wall surface of the oil suction passage for heating engine oil sucked from an oil sump of an engine lubrication device to an oil pump through the oil suction passage. The engine oil heating unit mounted on (1) is equipped with a screw-fastening structure that is liquid-tightly and detachably engageable with the opening formed in the wall surface of the oil suction passage, and has a base end. It has a hollow cylindrical shape that is closed by an insulating material and has an open tip, and has a radial through hole in the middle that communicates the inside and outside thereof, and the portion closer to the tip than the through hole is the oil. A metal main body that is inserted so that a gap remains in the suction passage, and (b) detachable inside the portion near the tip of the metal main body that is located in the oil suction passage. A hollow tubular positive temperature characteristic (PTC) electric heating element that is inserted and held; and (c) power supply means for supplying electric power to the PTC electric heating element from outside the base end of the metal body. , Removable engine oil heating unit, which is equipped with all. 2. The engine oil heating unit according to claim 1, wherein an outer electrode and an inner electrode are attached to the outer peripheral surface and the inner peripheral surface of the electrothermal heater element, respectively. 3. The plurality of slots extending in the axial direction over a predetermined length at the other end of the main body to increase the contact area between the outer periphery of the electric heater element and the oil. The engine oil heating unit according to claim 1 or 2. 4. The power supply means includes a cylindrical center electrode that is spaced radially inward from the main body, and a portion of the electrothermal heater element is detachably press-fitted between the main body and the center electrode. The engine oil heating unit according to any one of claims 1 to 3 which is claimed. 5. A cylindrical center electrode is provided with a plurality of T-shaped notches spaced apart from each other in the circumferential direction at the tip thereof, and the tip and the electric heater element are in elastic contact with each other. The engine oil heating unit according to any one of claims 1 to 4. 6. The main body is provided with a plurality of radial through holes downstream of the electric heater element so that heated oil inside the electric heater element flows from the inside to the outside of the electric heater element. What is claimed is: Claim 1
The engine oil heating unit according to any one of items 1 to 3. 7. A polygonal head is formed at the one end of the body,
The engine oil heating device according to any one of claims 1 to 6, wherein a wrench or other tool is engaged. 8. An engine oil is stored in the oil sump forming means to form an oil sump, and the oil of the oil sump is guided to the oil pump by an oil suction passage extending from the oil sump to the oil pump. In an engine lubrication device configured to supply oil to a movable portion of an engine by a pump to lubricate the movable portion, the oil suction passage includes an enlarged portion having a vertical one end wall and extending substantially horizontally. The vertical end wall of the enlarged portion is formed by a part of the oil sump forming means, the vertical end wall is provided with an opening portion that opens toward the enlarged portion, and the opening portion is provided with engine oil. The heating unit is liquid-tightly and removably mounted, and the engine oil heating unit includes (a) the oil suction passage. A hollow cylindrical shape having a threaded structure that is liquid-tightly and detachably engageable with the opening formed in the vertical end wall, and has a proximal end closed by an insulating material and an open end. And a radial through hole that communicates the inside and the outside of the intermediate part, and a portion closer to the tip than the through hole is inserted into the oil suction passage with a gap left in the periphery. Body, and (b) a hollow cylindrical positive temperature coefficient (PTC) electric heating element that is detachably inserted and retained inside the portion of the metal body located in the oil suction passage near the tip. And (c) power supply means for supplying electric power to the PTC electric heating element from the outside of the base end of the metal body, wherein the engine oil heating unit includes the electric heating element of the oil suction passage. The above It is positioned so as to be located in a large section, an engine lubrication system, characterized by being configured to heat the engine oil sucked in the oil pump by energization of the electric heater element. 9. The engine lubrication device comprises a relief valve for adjusting the pressure of oil discharged from an oil pump to a predetermined value, and a relief port of the relief valve is connected to an inlet of the enlarged portion of an oil suction passage. The engine lubrication device according to claim 8, characterized in that: 10. The oil sump forming means comprises an oil pan, and the enlarged portion of the oil suction passage is formed by a partition plate joined to the oil pan between a part of the oil pan and the partition plate. The engine lubrication device according to claim 8. 11. The engine lubrication device comprises an oil pump case, the oil pump case is extended downward to form an extension part, and the extension part and an oil pan constitute the oil sump forming means. 9. The engine lubrication device according to claim 8, wherein the extending portion constitutes the vertical end wall of the enlarged portion of the oil suction passage. 12. The engine lubricating system according to claim 8, wherein an outer electrode and an inner electrode are attached to the outer peripheral surface and the inner peripheral surface of the electrothermal heater element of the oil heating unit, respectively.