JPH02108508A - Manufacture of extendable and contractible shaft - Google Patents

Abstract

PURPOSE:To contrive obtain low friction, while slide feeling is improved and the feeling without rattling is kept for long time by a method in which inorganic lubricant and organic lubricant are dispersed in the raw monomer in molten state under heating and are simultaneously reacted thereto by using monomer casting method, and then the lubricants are compounded with the resin layer is uniform and stable dispersion, thereby forming the resin layer. CONSTITUTION:The lubricants of various kinds are added in a prescribed range into the tank storing the liquid A in which catalyst is added to epsilon-caprolactam as main raw material and the tank storing the liquid B in which initiation is added to epsilon- caprolactam or modified epsilon-caprolactam as main raw material. Said mixture is regulated and stored in dispersed state with mixing or molten state. Next, the liquid obtained by mixing the measured equal volumes of liquid A and B is poured into the preheated outer shaft 5 through a mixing and discharging part 3. A preheated inner shaft 6 is inserted into the outer shaft 5, while each spline 5C, 6C is caused to be concentric and the phase coincides mutually. The shaft 6 is inserted into the shaft 5 to a prescribed position, while it is accompanied by the rise of the liquid level 7 of monomer. Said shafts are kept in heating furnace 10 in that state, and the reaction is accelerated, thereby forming the resin layer 9 in which the lubricant is uniformly melted and dispersed in a gap 8.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a method of forming a resin layer on a sliding boundary layer by a monomer casting method, and relates to a method for forming a resin layer on a sliding boundary layer by a monomer casting method, and relates to a method for forming a resin layer on a sliding boundary layer using a monomer casting method. It is used in the production of resin layers.

(Prior art) As a prior art related to the present invention, Japanese Patent Application Laid-Open No. 61-18422
There is a No. 2 publication.

This slide spline device consists of an outer spline member having a bottomed cylindrical shape with a spline formed on the inner periphery and an inner spline, and the inner spline member is fitted into the outer spline member so as to be able to expand and contract. , the sliding surface is coated with a resin film to obtain a constant sliding resistance over a long period of time in the range where the inner spline member expands and contracts with respect to the outer spline member, and when manufacturing the slide spline device described above. Apply a mold release agent to the inner circumference of the outer spline member, then inject a monomer into the outer spline member, insert the inner spline member,
It is produced by displacing the liquid level of the monomer to a certain position via a clearance and polymerizing and curing the monomer.

(Problems to be Solved by the Invention) However, in the above manufacturing method, in order to improve the friction and wear characteristics of the resin layer, after forming the resin layer by a monomer casting method, grease is applied to the resin sliding surface. There are the following problems.

(1) During sliding boundary movement, grease gradually leaks from the sliding boundary, causing a lack of grease, resulting in a stuck-slip feeling and backlash due to abrasion of the resin layer due to the lack of grease. A feeling occurs.

(2) Since a resin layer is formed in the gap between the two members having an inner spline and an outer spline at the cash fitting position, there is only one set of proper fitting positions, and therefore the sliding member Unable to replenish grease with free.

(3) In the seven-layer casting method, the resin used, nylon 6, is hygroscopic and the base metal surface of the resin layer tends to rust.

The present invention is a technical method for manufacturing a low-wear telescopic shaft that improves the sliding feeling and maintains a feeling without rattling over a long period of time using a resin layer formed by applying the seven-point casting method. This is an issue to be addressed.

[Structure of the invention]

(Means for solving the problem) The technical means taken to solve the above problem are as follows. That is, in a method for manufacturing a telescopic shaft in which an inner shaft is slidably disposed within an outer shaft, in order to eliminate play between the two shafts, a space between the two shafts in a fitted state is removed. When forming a resin layer by applying the monomer casting method, inorganic lubricants such as molybdenum disulfide, graphite, and mixtures thereof are dispersed and suspended in the raw material monomer in a heated and molten state, or trifluoride ethylene tetrafluoride is used. Resin powders such as ethylene, hydrocarbons, fatty acid compounds (amides, esters, alcohols), organic lubricants such as metal soaps, and mixtures thereof are dissolved or dispersed and reacted to form a homogeneous or stable dispersion in the resin layer. A retractable shaft is manufactured by adding a lubricant.

(Function) In the 7-mer casting method and the nylon 1,000-mer casting method used therein, ε-caproculatum is the main raw material, and alkali metals such as metallic sodium, metallic potassium, ethylmagnesium bromide, alkaline earth metals, and These are liquid A to which organometallic compounds and hydrogen compounds have been added, and also ε-caproculatum or modified ε~ to which soft segments have been introduced to improve physical properties.
Equal amounts of solution B containing caproculatum as the main raw material and an acyl compound or isocyanate compound such as N-acetyl ε-caproculatum as an initiator are weighed and mixed.
A nylon resin is obtained by heating at 40 to 170°C and holding for 1 to 3 minutes to accelerate polymerization, and a resin layer is formed with the resin to which various organic and inorganic lubricants are added. As a result, a telescopic shaft with improved sliding feeling and low wear can be manufactured.

(Example) Examples will be described below.

In FIGS. 1 and 2, a liquid A storage tank 1a to which a catalyst has been added, a liquid B storage tank lb to which an initiator has been added,
In a two-liquid metering unit and discharge device 1 consisting of a pump 2 a i2b and a mixing discharge unit 3 for A and B liquids, 0.1-10% by weight of various lubricants are added to A and B liquid storage tanks la and lb.
The mixture is added in a range of 100 to 100 ml, mixed and dispersed using stirrers 4a and 4b, or adjusted to a dissolved state and stored.

Next, equal amounts of the A and B liquids are measured and mixed, and the mixture is fed to the mixing discharge part 3 to the outer shaft 5 of the two structural members, the outer shaft 5 and the inner shaft 6, which are preheated to 140 to 170°C. Inject via.

By fitting the outer shaft 5 and the inner shaft 6 with the respective splines 5c and 6c coaxially and in phase with each other, the monomer liquid level 7 is increased and the inner shaft 6 is fitted to a predetermined position. ~17
The mixture is kept in the heating furnace 10 at 0° C. for about 3 minutes to promote the reaction.

As a result, a resin layer 9 in which the lubricant is homogeneously dissolved or dispersed is formed in the gap 8 between the fitted outer shaft 5 and inner shaft 6, resulting in a smooth sliding feeling without rattling and a telescopic shaft with less wear. 20 can be manufactured.

Example-1 A prepared by dissolving 1 kg each of both components A and B at 100°C.

30 g of commercially available zinc stearate, equivalent to 3% by weight, was added to each of the liquid B storage tanks and maintained in a stable suspended state in a semi-molten state while stirring.

This adjusted mixed solution 5 of A and B in equal amounts is injected into the outer shaft preheated to 160°C, and immediately the inner shaft, which has also been preheated to 160°C, is placed coaxially and in phase with the outer shaft. They were fitted to the desired position, and then heated and held at 160° C. or lower for 3 minutes to obtain the desired resin composition and elastic shift.

This telescopic shaft exhibited a smooth sliding feeling with little stick-slip, and had a low amount of wear with no looseness even after 75,000 sliding tests.

Example 2 50 g of low molecular weight tetrafluoroethylene (Daikin Lubron 2 micron powder) was added to the liquid B storage tank, which has a high raw material viscosity, to give a concentration of 5% by weight, and stirring was continued to prevent sedimentation. The same procedure as in Example 1 was followed to obtain a telescoping shaft having a resin layer having the desired composition, and the same good results in friction and wear characteristics as in Example 1 were obtained.

(Comparative example) A telescopic shaft made of a resin layer without any lubricant was manufactured using the same procedure as in Example 1. The characteristic was that a stick-slip-like catching feeling occurred, and 75,000 pieces were tested. After that, there was a noticeable rattling due to wear.

〔Effect of the invention〕

The present invention has the following effects. That is, (1) since the lubricant exists uniformly in the entire resin layer or the surface layer, the lubricating effect such as a smooth sliding feeling and low wear is maintained.

(2) Since the lubricant can be added to the monomer raw material all at once, there is no need to apply grease to each molded product as in the past, and no application equipment is required.

(3) The lubricant uniformly dissolved or dispersed in the resin layer improves the hygroscopicity of the resin layer, and at the same time, the rust-inhibiting effect of the lubricant eliminates rust on the base metal surface of the resin layer.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of a storage tank in which lubricant is added and stored, and a device for measuring, mixing and discharging raw materials, and Fig. 2 is an explanatory diagram of the process of manufacturing a retractable shaft made of a resin composition containing lubricant in a heated atmosphere. 3 are enlarged explanatory views of the main parts of FIG. 2. 5... Outer shaft. 6... Inner shaft. 8...Suki. 9...Resin layer.

Claims (1)

[Claims] In a method for manufacturing a telescopic shaft in which an inner shaft is slidably disposed within an outer shaft and has a resin layer, in order to eliminate play between the two shafts, a gap between the two shafts in a fitted state is removed. When forming the resin layer by applying the monomer casting method, the inorganic lubricant and the organic lubricant are reacted while being dispersed in the raw material monomer in a heated molten state, and the lubricant is uniformly or stably dispersed in the resin layer. A method for manufacturing a telescopic shaft in which a resin layer is formed by compounding.