JPS5925841B2 - rotary piston engine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rotary piston engine, and more specifically, the present invention relates to a rotary piston engine that combines a rotor housing with a composite porous chrome plating of pinpoint type porous and channel type porous on the trochoid surface, and a hard apex seal. This provides sufficient sliding performance between the rotor housing and the apex seal even under sliding conditions worsened by the use of leaded gasoline.

As is well known, in a rotary piston engine, the rotor slides on the inner circumferential surface of a trochoid-shaped rotor housing while performing planetary rotation, and the apex seal and the inner circumferential surface of the rotor housing are subject to mechanical damage caused by vibration, shock, and friction. In addition to the load, the rotor housing is placed under harsh conditions where it is directly exposed to thermal loads such as thermal shock and thermal expansion due to explosive combustion. There were drawbacks such as abnormal wear called chatter marks, as well as scratches and wear.

Various countermeasures are currently being taken to address these shortcomings, such as improving the hardness balance between the apex seal and the chrome plating on the inner circumferential surface of the rotor housing, and making the chrome plating surface porous (pinpoint type or channel type) for lubrication. Performance has been improved and the occurrence of chatter marks has been greatly reduced compared to the previous model.

On the other hand, in Japan, fuel gasoline has been made lead-free to prevent pollution, and now regular gasoline is completely lead-free.

The above-mentioned measures to prevent the occurrence of chatter marks by making the chrome-plated surface channel-type or pinpoint-type porous were developed while using unleaded gasoline.Leaded gasoline is still used in other countries. has not been considered.

It is generally believed that the tetraethyl lead in leaded gasoline acts as a lubricant on the walls of the combustion chamber, improving wear resistance, but as a result of experiments, it has been found that It was found that it has an adverse effect on porous chrome plated surfaces.

It was found that the cause of this adverse effect was that lead compounds produced during gasoline combustion adhered to the porous plating surface, blocking the open ends of the independent pores and blocking the channel grooves, resulting in a decrease in the lubricating function.

For engines, pinpoint type porous chrome plating, which features independent pores, is disadvantageous to the spreadability of lubricating oil, so if leaded gasoline is used, the lubricity deteriorates due to the action of lead, resulting in a chatate mark. is likely to occur.

In addition, channel type porous chrome plating with continuous grooves improves the spreadability of lubricating oil and prevents chatter marks from occurring even when using leaded gasoline, but it also reduces lubricity due to oil path blockage and increases plating hardness. In some cases, the grooves become very fine and lack the ability to retain lubricating oil, making them prone to scratches.

As a result of various experimental studies to solve the above-mentioned problems, this invention maintains its function as an oil supply base even if the open ends of the independent pores are blocked, and on the other hand, even if the channel grooves are cut off in the middle, oil can be supplied from both sides of the grooves. We have succeeded in obtaining a porous shape that allows a sufficient supply of lubricity and prevents the overall lubricity from decreasing.

Specifically, in order to prevent chatter marks and scratches when using leaded gasoline, pinpoint type porous and channel type porous are made to coexist in an appropriate proportion to compensate for their respective disadvantages. The inner peripheral surface of the rotor housing has the scratch resistance of pinpoint type porous against leaded gasoline and the chatter mark resistance of channel type porous, and even if the lubricity is deteriorated by leaded gasoline, it will not be affected. To provide a rotary piston engine characterized in that the hardness of both the inner circumferential surface of a rotor housing and an apex seal is improved so that chatter marks and scratches do not readily occur, and the hardness is harmonized with high hardness.

Specifically, the rotary piston engine according to the present invention has carbide on the sliding surface of 50 to 70% and has a hardness of Hv.
The apex seal is made of a cast iron-based material with a hardness of Hv 930-1200 and has pinpoint type pores with a porosity of 5-40 and channels with a porosity of 5-40. The total porosity is in the range of 10 to 60, and the ratio of both types is 1:3 to 3:1, preferably 1:2 to 2:1.
It is combined with a rotor housing that is designed to be within the range of .

Hereinafter, the present invention will be explained in detail with reference to the drawings.

As shown in FIG. 1, the trochoidal inner peripheral surface of the rotor housing 1 is covered with pinpoint type porous plating having independent pores 2, and grooves 3 communicating with the pores 2.
Both channel type porous plating is applied, and pores 2 and grooves 3 are mixed.

In the process of forming the inner circumferential surface, as shown in FIG.
~ ~1200 chrome plating is performed, then reverse electric treatment is performed to form fine cracks, and then grinding is performed to create pinpoint type porous chrome plating (no. Figure 2 III).

Next, the surface of this pinpoint type porous chromium plating is subjected to reverse electric treatment again to form a fine channel type porous structure having a porosity of 5 to 40 and a structure 3 that is continuous with each other and also continuous with the pores 2. Composite porous chrome plating with a mixture of pinpoints (pores 2) and channels (grooves 3), with a total porosity of 10 to 60.
The ratio of pinpoint to channel should be 1:3 to 1:3.
The ratio is 3:1.

(Figure 2 ■) The various limiting conditions described above were specified for the following reasons.

(1) The hardness of the chrome plating is set to Hv 930 to 1200 because if it is less than Hv 930, chatter marks and scratches will occur, and if it exceeds Hv 1200, wear on the apex seal side will increase.

That is, for example, as shown in FIG. 8, the hardness of the apex seal is Hv700. As a result of a chatter mark generation test with a total porosity of 10, a ratio of pinpoint type and channel type of 1:1, and the same test conditions as described below, as shown by solid line a, when the hardness of chrome plating is less than Hv 930,
This exceeds the limit value of 5μ, which is set in view of the reduction in engine output and the generation of scraping noise, making it impossible to use it as a practical engine.

In addition, the hardness of Apex Seal is Hv900. Total porosity 1
0 ratio, pinpoint type to channel type ratio 1:
1 and under the same test conditions as described later, the results showed that the hardness H of the chrome plating was as shown by the dotted line in Figure 8.
If VV is less than 930, the depth of the scratch exceeds the limit value of 10μ, which is determined from the viewpoint of reduced output, and the engine cannot be used as a practical engine.

Furthermore, as shown in FIG. 9, the hardness of the apex seal is Hv700. We conducted an apex seal wear test using a total porosity of 10, a ratio of pinpoint type to channel type of 1:1, and the same test conditions as the chatter mark generation test described below. It has become clear that at Hv1200 or higher, the thickness of the surface chill layer of the apex seal exceeds 2.3 mm, causing rapid wear.

(2) Pinpoint type porous plating is necessary to prevent the occurrence of scratches, and the reason why the porosity is set to 5 to 40 is that if it is less than 5, sufficient scratch resistance cannot be obtained. The reason why the upper limit is set to 40 is to prevent the surface from becoming rough and the wear of the chrome plating to increase when applying channel type porousness by applying a reverse current again.

That is, as shown in FIG. 10, the hardness of the chrome plating is Hv1200, and the hardness of the 7PEX seal is Hv900. As a result of a scratch generation test with a channel type and pinpoint type ratio of 1:1 and the same test conditions as described below, the pinpoint type porous chrome as shown by the solid line a.
When the porosity of the plating was less than 5 tfl), the scratch depth reached the above-mentioned limit value of 10 microns.

In addition, the hardness of chrome plating is Hv-930, and the hardness of Apex seal is Hv900. As a result of an abrasion test of chrome plating with a pinpoint type to channel type ratio of 2:l and under the same test conditions as the chatter mark generation test described later, the porosity of the pinpoint type was as shown by the dotted line in Figure 10. If the thickness exceeds 40, the thickness of chrome plating is 6.
It was found that wear exceeds 0μ.

(3) Channel type porous chrome plating is chatter
It is necessary to prevent the occurrence of marks, and the porosity is 5
The reason for setting the upper limit to 40 parts is that if it is less than 5 parts, sufficient chatter mark resistance cannot be obtained, and the upper limit is set to 40 parts in order to maintain the total porosity in the range of 10 to 60 parts.

That is, as shown in FIG. 11, the hardness H of chrome plating
v930. Apex seal hardness Hv700. As a result of a chatter mark generation test using a pinpoint type to channel type ratio of 1:1 and the same test conditions as described below, it was found that when the porosity of the channel type is less than 5, the depth of the chatter mark decreases the engine output. It was found that this value exceeds the limit value of 5μ, which is determined from the viewpoint of the generation of scraping noise.

(4) The reason for setting the total porosity to 10 to 60 aI is that this range is the range in which porous chromium plating effectively acts on the trochoid surface, and if it is less than 10, the amount of lubricating oil retained is small, so the lubricity is low. As a result, chatter marks and scratches occur beyond permissible limits, and the amount of wear increases.

Moreover, if the ratio exceeds 60, the sliding area will decrease, the surface pressure during sliding of the apex seal will increase, and the amount of wear will increase, which is not preferable.

That is, as shown in FIG. 12, the hardness of chrome plating is Hv930. The hardness of Apex Seal was Hv700°, the ratio of pinpoint type to channel type was 1:1, and we conducted a chatter mark generation test under the same test conditions as described below.As shown by the solid line a, chatter marks appeared when the total porosity was less than 10 parts. The depth is 5μ or more, which is the above-mentioned limit value.

Also, the hardness of chrome plating is Hv930. The abrasion test of the chrome plating was conducted under the same conditions as the chatter mark generation test described later, with hard iHv 900 of the Apex seal, pinpoint type and channel type ratio of 2:1, and the result was as shown by the dotted line in Figure 12. It has been found that when the total porosity exceeds 60 parts, the thickness of the plated layer exceeds 60 parts and wears out.

(5) The reason why the ratio of pinpoint type porous to channel type porous is within the range of 1:3 or 3:1 is to give a synergistic effect of the advantages of each type, as is clear from the experimental examples described later. If the ratio of pinpoint type porosity is high outside this region, chatter marks will occur, and if the ratio of channel type porosity is high, scratches will easily occur.

These relationships will be explained with reference to FIG. 7, which will be described later.

The preferable porosity and ratio of the above-mentioned pinpoint type porous and channel type porous are shown in Fig. 3, and the total sliding surface area of the rotor housing is defined as S.
, pinpoint) If the pore area of the lve porous is 81 and the pore area of the channel type porous is 82, the following limiting conditions are met.

The preferable ratio of both of the above is as shown by the chain line in the figure, and is as follows.

The apex seal 4 shown in FIG. 1, which is in sliding contact with the trochoidal inner circumferential surface of the rotor housing described above, is made of a cast iron-based material with a sliding surface containing 50 to 75 volumes of carbide and a hardness of 700 to 900 Hv.

The limiting conditions for the apex seal mentioned above were specified for the following reasons.

That is, in a rotary piston engine that uses leaded gasoline, the apex seal is subjected to harsh sliding conditions, and the deterioration of lubricity due to the formation of lead compounds causes direct metal contact between the apex seal and the chrome plating. Causes scratches and chame marks.

For this reason, it is desirable that the sliding surface of the apex seal has a large amount of non-metallic material, and it must also have excellent wear resistance, and the hardness must be slightly lower than that of the chrome plating on the rotor housing. is necessary.

The material for the apex seal that satisfies these requirements is preferably a cast iron-based alloy material due to its compatibility with chrome plating.

The reason why the amount of carbide is set at 50 to 75 capacity is because if it is less than 50, there will be more parts that come into contact with metal when using leaded gasoline, and scratches and chatter marks will occur more than the allowable limit. This is because if it exceeds 100%, it will not be possible to contain carbides, making it difficult to manufacture, and the strength and toughness will decrease.

That is, as shown in FIG. 13, the hardness H of chrome plating
v930. As a result of conducting the same chatter mark generation test as described below with a total porosity of 10% and a channel type to pinpoint type ratio of 1:1, as shown by the solid line a, when the amount of carbide is less than 50%, the depth of the chatter mark is The thickness exceeded the above-mentioned limit value of 5μ.

The reason why the hardness was set to Hv700-900 is because if the hardness is less than Hv700, the wear resistance will be insufficient when using leaded gasoline.
If the Hv exceeds 900, the hardness will be too close to that of the chrome plating on the rotor housing, resulting in an imbalance in hardness, increasing the amount of wear on the chrome plating, and making the chrome plating more susceptible to scratches when there is insufficient lubrication. be.

That is, as shown in Fig. 14, the chrome hardness Hv
1200. Channel-type to pinpoint type ratio 1:1. We conducted an apex seal wear test with a total porosity of 10% and under the same test conditions as the chatter mark generation test described below.As shown by the solid line a, when the apex seal hardness is less than Hv 700, the apex seal has a chill layer thickness of 2. It was found that wear occurred rapidly beyond the 3 dragons.

In addition, the hardness of chrome plating is Hv930. Ratio of pinpoint type and channel type is 2:1. As a result of a wear test of chrome plating with a total porosity of 60 and the same test conditions as the chatter mark generation test described later, it was found that if the hardness of the apex seal exceeds 900 Hv as shown by the dotted line in Figure 14, the thickness of the chrome plating It was found that the wear exceeded 60μ.

Next, examples of the present invention will be listed in the table below, and the present invention will be described in detail in comparison with conventional examples.

The pinpoint manufacturing process is performed under reverse electric current and honing conditions such that the porosity is 5 to 40.

In addition, for the reverse electric charge in the step of pinpointly imparting channels, the current amount needs to be in the range of 25 AM/dwl-150 AM/dm'' for the following reason under the above bath composition conditions.

(1) 25 AM/d w? If it is less than that, sufficient channel type cannot be obtained to effectively act on the sliding surface.

(2) If it exceeds 150 AM/d, the composite porous chromium plating surface tends to collapse and has a negative effect on the sliding surface.

The plated surface of the inner peripheral surface of the rotano housing completed by the above manufacturing process is shown in the 100x micrographs of FIGS. 4I and IF.

As is clear from this photo, the porosity is 20° in Photo I showing Example 1, and the ratio of pinpoints and channels is 1.
:1, and in the photograph ■ showing Example 2, the total porosity is 50.
The ratio of pinpoint to channel is 2:1.

The rotor housing of each of the above embodiments was assembled as a rotary piston engine, and various comparative tests were conducted under the same conditions as those of the conventional example shown below.

In Conventional Example 1, pinpoint type porous chrome plating was applied to the inner peripheral surface of the rotor housing with a porosity of about 50, and in Conventional Example 2, channel type porous chrome plating was applied with a porosity of 2001). This is what I did.

In addition, the apex seal used in each of the above embodiments 1.2 and conventional examples 1 and 2 contains C3, OZ, and 2.2% Si.
+ Mn 0.7% s N 12-0% x Mo
O-8% s Cu 1. It is made of acicular cast iron with the remainder being Fe, and its sliding surface is chilled to have a carbide content of 65% by volume and a hardness of Hv 850.

A rotary piston engine consisting of the above combination of rotor housing and apex seal was subjected to the following tests, and the results were compared.

(1) Chatter mark generation test using leaded gasoline Test conditions Using an engine with a single-chamber volume of 573 cc, a 20-liter model, and an output of 125 PS, the rotation speed was increased from 3000 rpm to 7000 rpm with the accelerator fully open and under full load. After holding the RPM for about 40 seconds, release the accelerator to 3000
The process of lowering the rotation speed to rpm is one cycle (the water temperature is also changed), and this is 9000 cycles (this is
This corresponds to the engine lifespan that allows for sufficient safety in actual use.

), the engine was disassembled and inspected and measured.

The test results are shown in the table of FIG.

As is clear from this table, when leaded gasoline is used, large chatter marks occur in pinpoint type Conventional Example 1, whereas chatter marks occur in both examples of the present invention.
The amount of marks generated is small, especially in the case of Example 2,
The amount generated is minute.

(2) Test for scratch occurrence due to use of leaded gasoline Test conditions The vehicle was operated for 100 hours at 800 rpm in an idle state with no load and while maintaining the cooling water temperature at 30°C.

The test results are shown in the table of FIG.

As is clear from this table, conventional example 2 of channel type
In contrast, in the case of Example 2, large scratches were generated, but in all of the Examples of the present invention, the number of scratches was small, and in particular, in the case of Example 2, the amount of scratches generated was very small.

As is clear from the two types of tests described above, the embodiments of the present invention can prevent both chatter marks and scratches on leaded gasoline.

The table of FIG. 7 shows the results of an experiment on the relationship between chatter mark depth and scratch depth and the pinpoint to channel ratio when using leaded gasoline.

As is clear from this table, the ratio of both is 3:1 to 1:
A range of 3, particularly a range of 2:1 to 1:2, is a preferable range since both chatter marks and scratches are shallow in depth.

That is, the hardness of chrome plating is Hv930. Apex seal hardness Hv700. When the total porosity is set to 20,
The ratio of pinpoint type and channel type is 3=1
As the pinpoint ratio increases further, chatter occurs.
If the depth of the mark exceeds the above-mentioned limit value of 5μ, the engine output will decrease and the friction noise will become louder.

In addition, the hardness of chrome plating is Hv1200. Apex seal hardness Hv900. When the total porosity is 20cm, when the ratio of pinpoint type to channel type becomes larger than 1:3, the depth of the scratch exceeds the above-mentioned limit value of 1.0μ, and the engine output decreases. bring about.

As is clear from the above description, the rotary piston engine according to the present invention is constructed by combining a rotor housing whose inner peripheral surface is coated with a composite porous chrome plating of pinpoint type porous and channel type porous, and a highly hard apex seal. It has the advantage of exhibiting sufficient chatter mark resistance, scratch depth resistance, and abrasion resistance even when leaded gasoline is used.

[Brief explanation of the drawing]

Figure 1 shows -WM? of the rotor housing and ax seal of the rotary piston engine according to the present invention. ffi,
@2[ff1I ~Iv&! /p7, tsu, 7 ke. Fig. 3 is a graph showing the correlation between the porosity of the pinpo/India type porous and the porosity of the channel type porous, and Fig. 4 I shows the example of the present invention. FIG. 5 is a table showing the results of a chatter mark generation test between an embodiment of the present invention and a conventional example, and FIG. 6 is a table showing the results of a scratch mark generation test between an embodiment of the present invention and a conventional example. Figure 7 is a graph showing the correlation between chatter mark depth and scratch depth and channel type porous and pinpoint type porous, and Figure 8 is a graph showing the correlation between chatter mark depth and scratch depth and channel type porous and pinpoint type porous. Graph showing the relationship between scratches. Figure 9 is a graph showing the relationship between chrome plating hardness and apex seal wear. Figure 10 is a graph showing the relationship between porosity and scratch depth of pinpoint type porous and chrome plating. A graph showing the relationship between wear. Figure 11 is a graph showing the relationship between porosity of channel type porous and chatter mark depth. Figure 12 is a graph showing the relationship between total porosity and chatter mark depth and wear of chrome plating. Figure 13 is a graph showing the relationship between the amount of carbide in the apex seal and the depth of chatter marks, and Figure 14 is a graph showing the relationship between the hardness of the apex seal and the abrasion of the apex seal and the wear of the chrome plating. It is a graph showing a relationship. 1... Rotor housing, 2... Pore, 3... Groove, 4... Apex seal.

Claims (1)

[Claims] 1. Pinpoint type pores with a porosity of 5 to 400 and channel type pores with a porosity of 5 to 40 on the inner peripheral surface of chrome plating with a hardness of Hv 930 to 1200. Within the range of io to 60 and the ratio of both types above to 1
:3 to 3:1, and an apex seal made of a cast iron-based material with 50 to 75 volume percent carbide on the sliding surface and a hardness of Hv 700 to 900. A rotary piston engine. 2. The rotary piston engine according to claim 1, wherein the ratio of the pinpoint type pores to the channel type pores is within a range of 1:2 to 2:1.