JPS6063349A - Moving valve member for internal-combustion engine - Google Patents

Abstract

PURPOSE:To obtain the titled valve member having improved wear and scuffing resistances by specifying the ratio between hard and binding phases and using a solid soln. consisting of MoC and WC as the hard phase and an iron group metal contg. a solubilized specified metallic element as the binding phase. CONSTITUTION:At least a part of a moving valve member for an internal-combustion engine contacting with the opposite member is made of a carbide-base sintered alloy consisting of 60-90 wt.% hard phase and the balance binding phase. The hard phase is a solid soln. consisting of MoC and WC, and the binding phase is one or more kinds of iron group metals contg. 1-20 wt.% one or more kinds of solubilized elements selected among Al, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo and W. It is preferable to regulate the weight ratio of the amount of C contained in MoC and WC in the hard phase to the theoretical amount of C to 0.80-0.95 and the molar ratio of MoC/WC to >=1. A moving valve member of high quality hardly attacking the opposite member can be obtd.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention is a member that intercepts the valve mechanism of an internal combustion engine such as an automobile, and in particular, requires high wear resistance due to sliding contact with a cam. This relates to valve train members such as rocker arms and pulp lifters.

(Prior Art) Conventionally, in internal combustion engines installed in automobiles, etc., the base portions of valve train members such as rocker arms and valve lifters are generally made of carbon steel, alloy iron, cast iron, etc. . And the mating material of the valve train member (for example, a cam)
In order to increase wear resistance, carburizing, chill hardening, hard chrome plating, etc.
Alternatively, treatments such as thermal spraying with a self-fusing alloy are applied.

However, those that have been carburized and quenched have poor scuffing resistance, those that have been chill-hardened have poor durability, and those that have been plated with hard chromium have the drawbacks of peeling and abrasion peeling due to localized BiS. In contrast, self-support (
'J, those sprayed with alloys are less aggressive to opponents, [
As a result, the wear of Xf4+ material becomes severe (L).In this way, all conventional valve train parts are given 10 points for material gaps, and the valve train has better compatibility. There was a strong demand for the development of IS.

(Object of the Invention) The present invention has been developed in view of the above-mentioned circumstances. (It is the first thing, and its purpose is to have excellent abrasion resistance 1/J and scuffing resistance, and to reduce the opponent's attack and reed (-1).
Njr quality internal combustion engine fQIl valve system - IA'c J
4+! It is about providing.

(of invention) l':'¥sei) In other words, the basic 41qs composition of Ki-ni tsu, l is the other party's 42
In the internal combustion 412-related valve train P13 material having a contact surface metal, at least the contact surface portion is made of a hard phase 60~
90 weight percent (wt%) remaining fXll bonded phase!
The hard phase is composed of a solid solution of molybdenum carbide (MoC) and tungsten carbide (He~C), and the binder phase is Iron (Fe), Nickel (Ni), Cobalt (
The bonding phase is made of one or more selected from iron group metals such as Co, etc., and further contains aluminum in the binder phase.
Ni (At), titanium (Ti), zirconium (Zr)
), hafnium (1-1f), vanadium (V), niobium (INl), tantalum (1″a), rim (Cr
), molybdenum (Mo), and tungsten (W), at least one or two or more selected from 1 to 2
It is characterized by having 0 weight percent (wt%) solid solution.

41. Carbide-based sintered alloys made of such crystalline components are used for valve train parts. V with l+42 (for example, cam):>
By using it in 6ii, it is possible to improve wear resistance and distribution scuffing properties, reduce phase attack, and also ensure sufficient corrosion resistance required for valve train components.

Hereinafter, the valve train control according to the present invention will be explained in more detail.

In the valve train member of the present invention, the ash-based sintered alloy used at least in the direction of contact with the mating material is M as described above.
o Hard ke 4 phase consisting of solid solution of C and WC 60-9
0wt%, remaining 1tlll 14 cars selected from iron group metals such as Fe, Ni, Co, etc. J: 7 from tobacco 2+
[The bonding phase and the ill, during the introduction phase A4'l'i,
Zr.

Hf, V, Nb, 'l”a, Cr, Mo L
□ and W, &-, +: 2 or more types are dissolved in solid solution.

In the carbide-based sintered alloy of the present invention, the ratio of hard 7) ↓ is within the range of 60 to 9 Qwt. What is there?

This is due to the following reasons.

That is, when the hard phase is less than 60 wt %, the hardness and strength of the sintered alloy become low, resulting in poor surface jpfi wear resistance and single scuffing property. If the Mabuhi hard phase exceeds 9 [1 wt. Valve drive unit (such as A) has strong impact resistance* (unsuitable for what is required).

Therefore, in order to ensure excellent wear resistance and 11ij scuffing properties, as well as to reduce the impact resistance required for valve thread filtration materials, it is necessary to increase the proportion of the hard phase. It is necessary to satisfy the oak radius of 60 to 90% by weight.

The hard phase consisting of a solid solution of fX4oc and WC has a molar ratio of MoC and WC, that is, Pi1oC/WC.
'ff: It is desirable to set it to 1 or more, and the amount of carbon actually contained in the 4 casing phases, 840 and W
The weight ratio between the poem and the theoretical carbon amount obtained by equivalent calculation, that is, (containing carbon amount) / (theoretical carbon 1i Y), is 0.80 to 0.95 ψ・-1, and the song It is preferable to set it so that

It is desirable to set the molar ratio of C and WC to 71 or more because MoC is relatively inexpensive compared to WC and J: It is more economical to use a large amount of 1 to 10C in the hard phase. This is based on the following five reasons: ~10C is softer than WC, and therefore less aggressive to opponents.

In addition, the Oki two-phrase ratio between the amount of carbon content and the theoretical return cable door is 0.80.
The reason why it is preferable to be within the fl+α range of ~095 and within the curve is that if the weight ratio is less than 0.80, the hardness will decrease and the wear resistance will be poor. 0
If the temperature exceeds 95, the skin will become rough due to temperature/, C Geo 1
-1 = Due to the reason that the material will be significantly worn down.

On the other hand, in contrast to the hard phase, the binder phase accounts for 40 to 10 wt% of the remainder, and this binder phase binds the hard phase consisting of hard carbide to provide all the toughness required for valve train components. - (Fe, Ni, C from the viewpoint of bondability (sinterability), toughness, strength, etc.

14Φma/ζba2J selected from group a metals such as
! 1i J or more is used.

The bonded phase itself is corroded by the engine oil VC, but the hard phase is not corroded by the engine oil, so unevenness occurs on the pad coating surface (which is the surface that meets the mating material of the valve train system). In order to prevent this, A4'ri, Zr,
Hf, V, Nb, Ta, Cr, Ni.

If a selected small amount of W and W is dissolved in a solid solution of 1 to 20 wt% or more, the amount of the solid solution in the binder phase is set within the range of 1 to 20 wt%. The reason is that if it is less than 1 wt%, the sintered alloy will have poor side attack (the mating material will be severely worn down), and if it exceeds 20 wt%, it will reach the solubility limit in the binder phase and will precipitate as carbide, causing L7 to attack the mating material. Strong (because it does).

Furthermore, the sintered alloy used in the valve train member of the present invention is
Apparent hardness Hv2soo~1200, especially 600~10
It is desirable to set it within the range of 00. The reason for this is that if the apparent hardness is less than l-1vsoo, the 1i〃1゛S resistance will be inferior, and if the apparent hardness to1v exceeds 1200, the opponent's aggressiveness will decrease -) This is because it becomes unsuitable as a valve train member.

An example of the valve train member of the present invention made up of 1,100 G as described above is shown in the figure. Reference numeral 1 denotes a swing arm type rocker arm as a valve train member, and the part in contact with the valve 2 and the lash adjuster 3. The base portion 1A including the base portion 1A is made of carbon steel, alloy steel, etc. as in the conventional case. On the other hand, the portion that comes into sliding contact with the cam 4, that is, the pad portion 1B, is made of a carbide-based sintered alloy having the above-described structure. The pad portion 113 (c) made of this carbide-based sintered alloy is fixed to the base portion by
For example, divine means such as brazing, caulking, or casting and fixing are possible.

In addition to the rocker arm, the 1111 valve system member that has a contact surface with the cam may include a valve lifter, etc. Depending on the type and model of the valve thread part, not only the contact surface with the cam but also other parts may be used. The present invention can also be used for the part (rr) of the present invention.

(Example) The present invention will be further revised and explained below using examples and comparative examples.

Example 1 Solid solution powder in which the molar ratio of MoC and WC is 1 or more, that is, (1 to 100.7 ・Wo, s ) Cjltj
powder (hereinafter referred to as (Mo4'1l)C powder) or kl
'O2C powder/WC powder 70wt%, Co powder 14wt%
%, 14 wt % Ni powder, and 2 wt % Mo powder in a solvent. Next, this mixed powder gold was press-molded into a rectangular shape of 20 fins x 16 cm x 4 nm+, and then I
Sintered.

The obtained sintered alloy is fixed to the base of the rocker arm by brazing or other means, and then processed into a pad shape.
A 6-cylinder gasoline engine with an exhaust fj of 12,000 CC was installed and operated for 200 hours at an engine speed of 1.000 γpm and no load. In this way engine test)
After carrying out the test, the amount of pad wear and cam wear was measured.

Example 2 The molar ratio of ~loc and WC is 1 or more (Mo-W)
C powder 65wt%, Co powder 33wt%, Ta powder 2
Wet-mixed in a solvent at a blending ratio of wt%, produced a sintered alloy from the obtained mixed powder in the same manner as in Example 1, fixed it on the base of a rocker arm, and then processed it into a shape of a bar. A one-lane test was conducted in the same manner as above to measure the risk of pad wear and the amount of cam wear.

Example 6 The molar ratio of MoC and WC is 1 or more (N10.W)
C powder 80wt, CO powder 5wt, Ni powder 1
4wt powder and 1wt% At powder were wet-mixed in a solvent, and a sintered alloy was produced from the obtained mixed powder in the same manner as in Example 1, and after being fixed to the base of a rocker arm, a pad shape was formed. In addition, an engine test was conducted in the same manner as in Section 2, and the amount of pad wear and cam wear was measured.

Example 4 (MO・W)C in which the molar ratio of MoC and WC is 1 or more
Powder 84wt, CO powder 5wt, Ni powder 10wt
First, W powder was wet mixed in a solvent at a blending ratio of 1 wt%, and a sintered alloy was manufactured from the obtained mixed powder in the same manner as in Example 1, and after being fixed to the base of a rocker boom, it was processed into a band shape. However, an engine test was conducted in the same manner as above to measure the amount of pad wear and cam wear.

Example 5 When the molar ratio of MoC and WC is 1 or more,
C powder 60wt, W powder 20wt%, Ni powder 17w
t% and Ti powder at a blending ratio of 3wt$ in a melt bar, a sintered alloy was made from the obtained mixed powder in the same manner as in Example 1 of the actual hfli, and after fixing it to the base of a rocker arm, a pad was prepared. After processing into a shape, an engine test was conducted in the same manner as above, and the pano-dono W wear Jfi and the total cam wear amount were measured.

Example 6 The molar ratio of Mo C and WC is 1 or more (Mo-W)
C powder 72wt%, Co powder 13wt%, Ni powder 13wt%
wt%, ■Powder Zwt were wet mixed in a solvent, and the obtained mixed powder IJ was prepared in the same manner as in Example 1 to produce a sintered alloy, and after fixing it to the base of a rocker arm, it was shaped into a pad. The engine was tested in the same manner as above, and the amount of pad wear and cam wear was measured.

Example 7 (Mo.W)C in which the molar ratio of MoC and WC is 1 or more
Powder 65wt%, F”, C powder bed 15wt%, Ni powder 1
5 wt% of Cr powder and 5 wt% of Cr powder were wet mixed in a solvent, and a sintered alloy was produced from the obtained mixed powder in the same manner as in Example 1, fixed to the base of a rocker arm, and then processed into a pad shape. Then, an engine test was carried out on the same σ2 as above, and the throat wear 'ni: and cam wear -1
11, was determined as ii"jl.

Real; A11 Example 8 The molar ratio of N4oC and ~・VC is 1 or more (Mo・
W) Wet-mix 89wt% of C powder, IQwt% of CO powder, and 1wt% of Zr powder in a solvent, produce a sintered alloy from the obtained mixed powder in the same manner as in Example 1, and prepare a rocker arm base. After fixing it to the part, it was processed into a pad shape, and the amount of pad wear and the amount of cam wear was determined by υI11 using an engine test similar to the above.

Comparative Example 1 The molar ratio of MoC and wc is 1 or more (Mo/W)
A sintered alloy was produced in the same manner as in Example 1 from the a+ mixed powder by wet mixing in a solvent at a blending ratio of 95 wt% C powder, Awt% Co powder, and Iwt% W powder, and a sintered alloy was prepared in the same manner as in Example 1. After it was fixed, it was processed into a pad shape, and an engine test was conducted in the same manner as above to determine the amount of pad wear and cam wear.

Comparative Example 2 The molar ratio of MoC and WC is 1 or more (h40・)7
C) 55 wt% of C powder, 2 Dwt% of Ni powder, 20 wt% of C, O powder, and 5 wt% of Ta powder were wet mixed in a melting medium, and the obtained mixed powder was prepared in the same manner as in Example 1. After making a sintered alloy and fixing it to the base of the rocker arm, it was processed into a pad shape, and an engine test was conducted in the same manner as described in Section 2).
111 was established.

Comparative Example 3 (Mo:W)C in which the molar ratio of MoC and WC is 1 or more
A powder bed of 80 wt %, Co powder 15 wt %, and MO powder 5 W kon were wet mixed in a solvent, and a sintered alloy was produced from the obtained mixed powder in the same manner as in Example 1, and was applied to the base part of the rocker arm. After it is fixed, it is processed into a pad shape,
An engine test was conducted in the same manner as above to measure the amount of pad wear and cam Jlt wear.

Comparative Example 4 The molar ratio of N1oC and WC is 1 or more (Mo.W)
C powder 75wt, CO powder 12wt, Ni powder 12
A sintered alloy was produced in the same manner as in Example 1 from the mixed powder by wet mixing in a harsh medium at a blending ratio of 1 wt% of Mo powder and 1 wt% of Mo powder, and then fixed to the base of the rocker arm. After changing the shape of the band, an engine test was conducted in the same manner as in Section 2 to measure the amount of wear on the pad 713', the amount of wear on the cam, and the amount of wear on the cam.

The powder blend ratios, alloy properties, and engine test results of Examples 1 to 8 and Comparative Examples 1 to 4 are summarized in Table 1. In Table 1, in Examples 1 to 8, the intake ratio of the carbon content y (immediate carbon content) is 0.80.
~0.95), in pronation, hardness Hv 500~1
200's 1jtj'j, pronation and 7', c There is extremely little band wear.

In contrast, Comparative Example 1 is temporary! Quality 4 [+ one; I4. There was a lot of cam wear. Comparative Example 2 has less hard phase (
Pad wear was severe. Further, in Example 3 of Ratio 11, there was a large amount of MoM dissolved in solid solution in the binder phase, and bad j1≦wear was large. Furthermore, for Comparative Example 4, the blending ratio of the alloy powder itself is within the range of 8.0, but the ratio of (contained carbon content)/(theoretical carbon content) in the hard phase is IIt.
The ratio was low at 065 (bad Jg": wear and cam J! No wear were both significantly thicker.

(Effects of the Invention) As described above, the carbide-based sintered alloy used in the valve train of the present invention has good side wear resistance and low aggressiveness against mating materials, so it Is the wear and scuffing of the contact surface with the material significantly smaller than before, resulting in a longer life? You can expect it. In addition, the wear of the mating material is reduced, and the corrosion resistance required for valve train components is also sufficiently ensured.

BRIEF DESCRIPTION OF THE DRAWINGS The figure is a side view showing an example of a valve train member of the present invention. 1...Rocker arm 1A...Base part 1C...-Pad part 4...Cam Patent applicant Toyota Motor Corporation Sumitomo Electric Industries, Ltd.

Claims (3)

[Claims] (1) A carbide-based sintered alloy in which the hard phase is 60 to 90% by weight and the remainder is a binder phase, 1) The hard phase in II is composed of a solid solution of MoC and WC, and
One binder phase is composed of one or more selected from iron group metals, and At is contained in the binder phase. Ti, Zr, Hf, V, Nb, Ta, C
At least one selected from r, Mo and W-1:
4. Internal combustion characterized by having 1 to 20% by weight of 1 to 20% by weight of or more than 2 elongation dissolved in solid solution.4. I*Seki valve train Itobori. (2) The weighting of the carbon content of MoC and WC in the hard phase and the theoretical carbon '3 is within the range of 0.80 to 11.95. Valve train components for internal combustion engines. (3) The molar ratio of N〆joC to WC in the hard phase, that is, MoC/WC is 1 or more, 4! ft￥F
Claim 1 map ζ refers to the internal combustion system 1 described in claim 2. ) Gate valve train components.