TD-627 Servo Inner Grooving Machine | CNC Tube Grooving for Gas Spring & Shock Absorber Cylinders
Gas spring damping groove (inner grooving): layouts, groove types and opening speed
What the machine does
Gas spring, shock absorber and damper cylinders carry several longitudinal oil grooves on the bore. Where the piston passes a grooved section, oil or gas bypasses it and the stroke is fast; where there is no groove, flow is damped and the stroke is slow. Groove length, depth, number and position set the tailgate opening curve, the feel of a chair lift or the damping curve of a shock absorber. TD-627 makes those grooves – also called damping grooves (拉槽 / 拉筋). Because the damping comes from the groove in the cylinder wall rather than an orifice in the piston, it works in any mounting position, horizontal or rod up.
How it works
The cylinder is fed automatically, clamped and located; the grooving mold enters the bore and a servo slide draws it along the axis, pressing the wall outward from the inside to form the groove – no chips. Depth is set by the servo feed, length by the servo stroke; after one groove the servo indexes the part for 180° double or 120° triple grooves. All parameters are set and stored on the touch screen, so a product change is a recipe recall with no mechanical reset.
Workpiece range
| Item | Spec |
|---|---|
| Workpiece | Gas spring, tailgate strut, gas lift, shock absorber and damper cylinders |
| Material | Cold-drawn precision steel tube, carbon steel tube |
| Tube OD | 15–28 mm |
| Tube length | 100–600 mm |
| Groove type | Longitudinal damping grooves: single, 180° double (symmetrical), 120° triple – up to 3 grooves, each with its own depth; 1–3 segments on the same line; groove types A (square), B (taper in, square end), C (taper in and out), D (segmented); length, depth, width and position set on the touch screen to drawing |
| Production examples | Cylinders OD15×1.0t×100L and OD28×470L (see videos) |
Servo or hydraulic
| Model | Drive | Best for |
|---|---|---|
| TD-627 | Servo | Many sizes, frequent changeovers, tight groove-depth consistency, production records |
| TD-61530 | Hydraulic | Fixed-spec, single-product tailgate strut and gas lift lines |
Features
- Automatic loading and unloading.
- Servo drive is not affected by oil temperature changes, for stable precision and repeatability.
- Single, 180° double and 120° triple grooves, plus 1–3 segment grooving on one line.
- Servo-controlled groove length and depth, identical from groove to groove and part to part.
- Product recipes stored on the touch screen; recall to change over.
- Automatic feeding; one operator can tend several machines.
- Tooling made to the bore diameter and groove width, supplied long term by TONG DA.
- Mitsubishi servo and PLC, serviceable worldwide.
Part of a cylinder line
Closing and grooving are the two core cylinder operations. TONG DA builds both the TD-31040 closing machine and the TD-627 grooving machine with matched clamping and location, so they are planned together; add TD-AT155 pressing and edge folding and TD-91528 lock nut for a complete gas spring cylinder line. TD-627 machines are running at gas spring and shock absorber makers in Turkey, India, Brazil and China.
Also known as
Inner grooving machine, damping groove machine, gas spring cylinder slotting machine, tube slotting machine, cylinder bore grooving machine, broaching machine, gas spring grooving machine, damper tube slotting machine.
Related: Gas spring production line · TD-627 damping groove types
Other names by market
USA / UK / India: inner grooving machine, internal grooving machine, tube inner grooving machine, damping groove machine, dynamic channel, dynamic channel machine, dynamic damping groove, gas spring grooving machine, gas spring cylinder slotting machine, cylinder slotting machine. Turkey: iç kanal açma makinesi, boru iç kanal makinesi, gazlı amortisör kanal açma makinesi, amortisör borusu kanal makinesi. Brazil: máquina de ranhura interna, ranhuradeira interna de tubos, máquina de canal de amortecimento, ranhura de amortecimento mola a gás. Spain / Mexico: ranuradora interna de tubos, máquina de ranurado interior, ranura de amortiguación. China: 拉槽机、拉筋机、气弹簧拉筋机、气弹簧拉槽机、内壁拉槽机. Taiwan: 拉槽機、管內拉槽機、伺服拉槽機、油壓拉槽機、缸體拉槽機.
FAQ
Can grooves have different depths?
Yes. Depth is a servo feed setting, so grooves on one cylinder can differ to give progressive damping.
Is the ring groove near the tube mouth also an inner groove?
No. The circumferential groove that holds the guide and seal near the open end is rolled from the outside on a tube rolling machine (TD-42815). The damping groove is the long axial groove inside the bore that controls speed.
How many bore sizes on one machine?
Change the tooling and fixture; one tooling set per bore diameter.
Close first or groove first?
Customers use both orders depending on cylinder design; TONG DA advises from your drawing.
Trial run?
Yes. Send cylinder OD × wall × material × length and the groove drawing (length, depth, number, position); we trial-groove and return samples.
Capacity, lead time and price?
Email sales@tdco.com.tw with the cylinder spec, groove drawing and expected quantity; we reply with full details.
